Suppose y varies directly with x where y = 21 when x = 7. Find x when y=72.

x = 24

Step-by-step explanation:

Given that y varies directly with x then the equation relating them is

y = kx ← k is the constant of variation

To find k use the condition y = 21 when x = 7, so

21 = 7k ( divide both sides by 7 )

3 = k

y = 3x ← equation of variation

When y = 72, then

72 = 3x ( divide both sides by 3 )

x = 24

10/60

step-by-step explanation:

if you divide 10 by 60 the answer is 0.166666 while if you divide or solve the other problems it equals 0.6