help with direct variation?

Question

If y=7.5 when x=.5 find y when x= -.3
If y= 80 when x=32 find x when y = 100
If y= 3/4 when x= 24 find y when x= 12

Please help

Answer 1

direct variation... that means that as x increases, so does y. You need to find the proportions of x to y if solving for x, or y to x if solving for y:

1) y = 7.5, x = .5, we are solving for y, so we need y/x = 7.5/.5 = 15

so -0.3 * 15 = -4.5 = y

2) y = 80, x = 32, solving for x so we need x/y = 32/80 = 2/5 =0.4

so 100 * 0.4 = 40 = x

3) y = 0.75, x = 24, solving for y so we need y/x = 0.75/24 = 0.03125

so 0.03125 * 12 = 0.375 = y (also = 3/8)

Answer 2

very confusing point. browse using a search engine. that will can help!