Question

Please help, I’m so lost in math

Answer 1

`r = 15 * 5 \\ r = 75`

Answer 2

75

Explanation:

5 = r/15

what we want to do is solve for r

to do this we want to isolate the variable (r) using inverse operations

5 = r / 15

so to solve for r we want to get rid of the 15

r is being divided by 15

the inverse of division is multiplication

so to get rid of the 15 we multiply by 15

but remember whatever we do to one side we must do to the other side, so we multiply each side by 15

15 * 5 = 75

r / 15 * 15 = r

we're left with r = 75

we can then check are work by substituting 75 for r and then see if the equation is true

5 = r/15

* substitute 75 for r *

5 = 75/15

75 / 15 = 5

we're left with 5 = 5 which is true