Solve each of the following

1.Y varies directly as x^2 if y=8 when x=2, find y when x=4

2. Y varies directly as x, if y=2.5 when x=7.25, find y when x=5.75.

3. V varies directly as the squares of w if v=25 when w=10, find v?

4. If r is directly proportional to (3s+1), and the corresponding values of r and s are 5 and 8 respectively, find r when s=-3.

5. The lift of an airplane I is directly proportional to the square of the air speed of s. If I is 250 when s= 100, find I when s=250.

1. Y = 32
2. Y = square root of 4.75
3. I think you typed question wrong
4. 2 or square root of 10
5. 1562.5

"varies directly" and "directly proportional" mean the relationship is y = k * x.

If y=8 when x=2, then k=4 and y = 4x.

If v is proportional to the square of w, then v = k * w^2
If r is proportional to (3s+1), then r = k * (3s+1)
etc.