Question

Which ordered pairs are on the line ​ 4x−3y=8 ​?

Select each correct answer
(1,−43) ​

​ (−4,−8) ​

​ (−1,4) ​

​ (32,−23) ​

I looked this answer up and I got -4,-8 but I do not understand how x and y are -4 and -8. Please explain how you got your answer.

Answer 1

Alrighty! So the correct answer is (-4, -8).

We know that x and y are -4 and -8, because when we substitute the first number in the set, which is -4, in for x, and we substitute the second number in the set, which is -8, in for y, we will get the answer 8=8

This is how this problem would be solved:

Step 1: Write out the equation

4x-3y=8

Step 2: Subtitute -4 and -8 for x and y

4(-4)-3(-8)=8

Step 3: Solve!

-16-3(-8)=8

-16+24=8

Answer: 8=8

Hope this helps! :)

Answer 2

4x-3y =8

check (1,-43)

4(1) -3(-43) =8

4 +139 =8

NO

check (-4,-8)

4(-4) -3(-8) =8

-16+24 =8

YES

check (-1,4)

4(-1) -3(4) =8

-4 +-12 =8

NO

check (32,-23)

4(32) -3(-23) =8

128 +69 =8

NO