The value of y varies directly with x. If x = 15, then y = 12. What is the value of y, when x = 21? A.26.25
B.16.8
C.0.8
D.1.25

The answers A

Step-by-step explanation:

Use ratios such that x1/y1= x2/y2

Need to find x2

So it works much easier if you use x as the numerator, giving 15/12=x/21

Multiply both sides by 21 and we have 21 x 15/12=x x 21/21

and 21/21=1 giving: x=21 x 15/12= 26 1/4

and in decimal form is 26.25

right

step-by-step explanation: