Leah is 2 less than 3 times Rachel's age. 3 years from now, Leah will be 7 more than twice Rachel's age. How old will Rachel be in 3 years from now?

15

Step-by-step explanation:

Let's call Leah's age l and Rachel's age r. We can write:

l = 3r - 2 (1)

l + 3 = 2(r + 3) + 7 (2)

Substituting (1) into (2) we get:

(3r - 2) + 3 = 2(r + 3) + 7

3r + 1 = 2r + 13

r = 12

In 3 years Rachel will be 12 + 3 = 15 years old.

so, converting firstly the mixed fractions to improper fractions and then "adding".

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)