Find the missing value in an ordered pair for a given equation

If you have an equation, I'll show you how to find the missing value of an ordered pair. Learn what the most common mistake is and how to avoid it, and how questions that look really similar can feel quite different to answer!

We'll consider the equation y = –2x + 3. We have four ordered pairs, but each of them is missing one of the two numbers, or values.

First, I'll review the "order" of ordered pairs: the first number is the x–value, and the second number is the y–value. We often write (x, y). I'll point out that this is opposite of the order that x and y appear in one of the most common representations of linear equations, slope-intercept form. I'll suggest using color-coding to avoid mixing up your x- and y-values.

We'll do two examples where we're given the value of x. These examples are a little bit easier, because if we substitute our given value for x, we just need to calculate to find our y-value.

We'll also do two examples where we're given the value of y. In these cases, we're trying to find the missing x-values, but our x is buried in the middle of the right side of the equation. So we need to isolate x, or solve the equation for x. We'll solve these equations algebraically, by subtracting 3 from both sides, then dividing both sides by –2.

[itsmagen]

You made me understand something in 8 minutes that my teacher couldn't in an hour

[je]

Thank you, doing both using the same equation makes it easy for me to see the difference between the two ❤

[MrSuperJayJay]

I was stuck on this in my homework. I love you

[Sairafaryad-nbgu]

learning this the night before the exam at 10:34 😂
Also ty so much this helped me alot😊

[yambichauhan]

Please answer this question
Find the missing value of X and y from the following equal ordered pairs. (X+2 y, 3)=(-1, 2 x- y)

[juliac.]

What if you have multiple ordered pairs (2)?