Algebra 1 gimkit

Question

Y varies directly with X. If y=7 and x=4 what is the value of y when x=12

Answer 1

As a proportion:

y/x = 7/4 = y/12

Cross-multiply: 4y = 84

y = 84/4 = 21

Answer 2

For direct variation

y = kx

k =y/x = 7/4

y = (7/4)x

when x = 12

y = (7/4)(12)