If y varies directly as x, and y=6 as x=-1, find y for the x-value of 5

The initial statement is y∝x

to convert the statement into an equation multiply by k,

the constant of variation

⇒y=kx

to find k, use the condition given

y=kx⇒k = yx

⇒k = 6 - 1 = - 6 the equation is 22 y=-6x 22 when x=5⇒y=-6*5 = - 30