Question

Suppose y varies directly as x. Write a direct variation equation that relates x and y. Then solve.

​If y = 21 when x = 14, find y when x = 40 .
ur answer should have ,60

Answer 1

see explanation

Explanation:

given y varies directly as x then the equation relating them is

y = kx ← k is the constant of variation

to find k use the condition y = 21 when x = 14 , then

21 = 14k ( divide both sides by 14 )

`(21)/(14)` = k , that is

k =
`(3)/(2)` = 1.5

y = 1.5x ← equation of variation

when x = 40 , then

y = 1.5 × 40 = 60