Math question: If X decreases by...

Question

Given the equation 5x+2y= 6

 

If x decreases by 4 units, what is the corresponding change in y?

 

If y decreases by 20 units what is the corresponding change in x?

Answer 1

5x + 2y = 6 ⇒ y = 3 - (5/2)x

 

y' = 3 - (5/2)x' = 3 - (5/2)(x - 4) = [3 - (5/2)x] + 10 = y + 10

 

So y increases by 10 if x decreases by 4.