If x

yz, and when y=-2, z=-3, x=30. when y=4, x=80. find z

Step-by-step explanation:

Given:

replacing the proportionality sign with a constant , we have :

substituting : , and into the equation , we have :

divide through by 6

substituting   into the equation , the equation becomes

To find the value of z , when y = 4 , x = 80 , we will substitute the values into the formula , we have :

dividing through by 20 , we have :

10

step-by-step explanation:

7+3=10

-13

step-by-step explanation:

f(x)=2x-5 for f(-4)

f(-4)   means let x=-4

f(-4) = 2(-4) -5

f(-4) =-8-5

      = -13