Question

n that represents the relations If y is directly proportional to x and y = -15 when x = 3, find the value of y when x is 20.

Answer 1

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form y=kx

where k is the constant of proportionality

we have that

y = -15 when x = 3, find the value of y when x is 20.​

so

step 1

Find teh value of k

k=y/x

For x=3, y=-15

k=-15/3

k=-5

the linear equation is

y=-5x

step 2

find the value of y when x is 20.

For x=20

substitute in the linear equation

y=-5(20)

y=-100