y varies directly as x, and y=7 when x=4, find y when x=12
Since y varies with x, the same we do to y, applies to x.
x = 4 y=7
x= 43 = 12
x= 73 = 21
Therefore, x = 21
Final answer: x=21 and y= 12
♥ Lets gather the information we know:
\(x = 4 y=7\)
♥ Now lets multiply and solve:
if x= 43 and 43 is 12
if x= 73 and 73 is 21
♥ And since 7*3=21, our answer is 21