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Grade 8 MATH Term 2 Week 5: Linear Equation in One Variable | MATATAG - 2nd Term/3rd Quarter Tagalog – Transcript
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[bell] Hello everyone, welcome Matt ACP YouTube channel where you can find free Tagalog mathematics tutorial. Our topic for today is all about linear equation in one variable. But before we begin, let me just remind everyone to please click the subscribe buttons.
And to those who have already subscribed, thank you very much for sharing also our videos to others, especially to our dear teachers. Thank you for sharing this to our dear learners. So without further ado, let's now begin with our lesson. All right, our competency for today is to solve linear equations in one variable. All right, so let's begin with a recall. So remember we already learned about algebraic expressions in grade 7. So
remember algebraic expression is a combination of variables, constants and operations. So we have here the examples. We have x + 3 where we have the variables x and you constant three. We also have here x - y where we have variables only and the operation subtraction. Me xy which means x * y. So it is still an algebraic expression. 2x
+ y wherein we have now multiplication and addition meaning 2 * x and then plus y. We also have here x over y which means x / y and then we have here exponents. We have a 2 + b ^ 2 meaning a * a and then b * b. Okay, so if we're going to add it, it will be a 2 + b ^ 2.
And we also have here expressions like 1 + 3 and then we have 4 + -6. Well, these are just what we call numerical expressions. But are they algebraic expressions? Algebraic expressions, it should have variables, constants, and operations.
Okay, let's have equation. Equation. Okay, remember equation is a mathematical statement that shows the two expressions are equal. Okay, that's why we have the word equation coming from the root word equal. So just like in a balance scale wherein one side will be equal to another side if they have the same weight. Just like for example here equal
we have here x + 3 and then we have here five value left side right side. Okay equation. Well here we have an unknown value which is x. Remember variable is unknown. We do not know the value. that whatever the value is value x it will make the statement true still equation. Okay. So whatever the
value of x here it will make the statement equal. So value x solving equation that we also have learned before. So when we solve equation it means finding the value of the unknown that makes the equation true. Canina we have here x + 3 is equal to 5. How are we going to get the value of x? Well x here is something that will make the statement true. So what will
you add to three para five? So it will be positive2. Okay. Therefore we have now 2 + 3 is 5. So 5 is equal to 5. The statement is now true. Solution solution equation. All right. Now let's have the properties of equality because this is also very important. Okay equation.
So remember we have the first one we have the reflexive property of equality which states that a is equal to a. Just like in a mirror if you face the mirror you will see your own reflection. Okay.
Reflexive property of equality. Okay. Next one we also have here symmetric property of equality which states that if a is equal to b then b is now equal to a. Okay it's just like a uh symmetrical figure like for example here the left side is symmetrical to the right side of a butterfly. So if a is equal to bal b is equal to a. Next we also have here
transitive property of equality. If A is equal to B and B is equal to C, then A is equal to C. Okay. Example, we have here three boys with their height. If boy A and boy B has the same height, if they have the same height and B have the same height with C, boy C, and boy A and boy C also have the same height. Okay, that is the meaning of transitive property of
equality. Another property is uh the addition and subtraction property of equality. Okay. So here some of the books they just use addition property of equality. But uh actually we can use subtraction property of equality.
Although they are almost the same. We have here if a is equal to b then a + c is equal to b plus c. Whatever we add on the left side of the equation right side. Now whatever we subtract on the left side of the equation just like this a minus c is subtract right side so b minus c as well. So addition
c and then subtraction c or any value. All right. Next illustration. If we have one person on the left side and then one person on the right side person left right para balance. Okay. What else we also have here? Multiplication and
division of property of equality wherein if we have here a plus a is equal to b I'm sorry then a * c is equal to b * c whatever we multiply on the left side it should be also be multiplied on the right side. and division. If a is divided by c then b is also divided by c. Same
okay divide both sides just like here. Okay. Left side right side. Okay. So those are the properties of equality that we are going to use in solving uh linear equations.
Okay. So again, if you haven't mastered these skills, you can actually go back to our previous videos. This is found in the grade 7 playlist on algebraic equations. Like for example, solving equations using the bar model, properties of equality, uh solving equations using properties of equality, and solving problems involving algebraic equations. You can always go back to this if you want to recall or review your lessons in grade 7.
Okay. So focus linear equation in one variable. So what is this? A linear equation in one variable is an equation that can be written in the form ax plus b is equal to c. Okay. Wherein a and b and c are real numbers. Okay. And a should not be equal to zero. I repeat we have here a b and c these are all uh
real numbers. And variable is variable x. is variable. Okay. And one more thing, a the first coefficient should not be equal to zero. Okay. Form linear equation in one variable. Let let us have examples. Salima, we have here 3x + 5 is equal to 11. So is this in the form a x + b is equal to c? Yes. Because we
have here the variable x and then ano value a we have here three and then uh five as our b and then 11 as our c. So they are all real numbers. 0 first coefficient. Ano pa. We also have here 7 x - 4 is equal to 10. So the only variable here is also x. We have the a which is 7, b which is -4 and then c which is 10. So not necessarily exactly
consider examples. No actually we can also have this example we have here x + 2 is equal to 6. Oh, so value C is 6 and value B is 2. But you might be questioning, you might be asking A. So here we don't have a number before X. But we know that if it is uh not written
1 coefficient. So our A is equal to 1. Ano P. We also have here 5X is equal to -20. So -20 here is C. No asan po B.
number or constant. Well, we can say that B is equal to zero. Okay. And if we're going to add zero here, it will be the same. Now, what will be our A? It is five. Okay. And remember, A should not be equal to zero.
B C 0 except for the first coefficient. Okay. Linear equation in one variable and it can be written in this form. A X + B is equal to C. Okay. Okay, just some additional notes. Okay, example hind linear equation in one variable. So no variable in a linear equation is raised to a power greater than one or use as
the denominator of a fraction or inside a radical. So take note linear exponent power. So examples we have here x^2 + 1 is equal to 5. This is not a linear equation. Why? Because the exponent here or the power the degree is 2 not 1. What else we have here? X raised to 3 is
equal to 12. Okay. Uh this exponent is not one. So therefore this is not a linear equation. We have here 4x= 3. This is also not a linear equation because the variable x is in the denominator.
Okay. uh in the in our linear equation. Nothing variable I numerator if it is in a fraction form. Okay. What else? We also have here the square root of x + 2 is equal to 5. This is not also a linear equation because the variable x is inside the radical. Okay.
All right. So there you go. Those are examples of not linear equations. Okay. For you to practice, I have here an exercise. You can pause this video if you want to answer this on your own. Determine whether each of the following equations is a linear equation in one variable. Write linear if it is and not linear if it is not. I'll give you time to do this and then later you can play this and then I'll give you the correct answers.
>> >> Okay, I hope you are now ready. Let's now find out the correct answer. Let's