Direct Variation #21

Question

Y varies directly with x and y is 20 when x is 5. Find the constant of variations, write variation equation and find y when x= -5, -1, and 10.

Answer 1

y = kx, k = constant

 

20 = k*5 ⇒ k = 20/5 = 4

 

y = 4x

 

x = -5:

 

y = 4(-5) = -20

 

x = -1:

 

y = 4(-1) = -4

 

x = 10:

 

y = 4*10 = 40