Question

If (x+3) varies directly as y and x=3 when y=12, what is the value of x when y=8?

Answer 1

x = 1.

Explanation:

y = k(x + 3)

When x = 3 y = 12 so

12 = k(3 + 3)

6k = 12

k = 2.

So the relation is y = 2(x + 3)

When y is 8:

8 = 2(x + 3)

2x = 8 - 2*3 = 2

x = 1.