Question

The value of y varies directly with x. If x = 3, then y = 21. What is the value of the constant of variation (c)?

a) 3/5
b) 1 and 2/3
c) 7
d) 15

Answer 1

The constant of variation (c) is found by dividing y by x which is 21 divided by 3, yielding a value of 7.

Step-by-step explanation:

The question provided states that the value of y varies directly with x. This means there is a constant of variation (c) such that y = cx. The problem gives us a specific pair of values: if x = 3, then y = 21. To find the constant of variation, we will plug these values into the equation and solve for c.

So we have:
y = cx
21 = c(3)
c = 21 / 3
c = 7

Therefore, the constant of variation c is 7.