Question

Let y=21 and x=1.5 if y varies directly with x find y when x=9

Answer 1

Y would be 42. if you multiple 1.5 by 3 it will be 9. so if divide 21 by 1.5 it equals 14 so multiple 14 by 3 it gives you 42

Answer 2

If
`y` varies directly with
`x` then we have the following function:

`y=x + (21 - 1.5)` or simply
`y = x + 19.5`.
So, when
`x=9`:

`y = 9 + 19.5 = 28.5`