If the value of y varies directly with x and y= -1 when x=3, find y if x=9

y = - 3

Since y varies directly as x then

y = kx ← ( k is the constant of variation )

to find k use y = - 1 when x = 3

k = = = -

hence y = - x

when x = 9, then

y = - × 9 = - 3

answer: since the question is talking about growth you have to use the growth formula which is inital amount (1 + growth)^time

step-by-step explanation:

the intial amount is 1200, the growth is 4.8, and the time is 7. plug those numbers into the equation, also i think you have to change 4.8 into a percent. but, i have forgotton how to do that. if this is a online class go on to the lesson.