Write 2/3 as an equivalent fraction with denominator 6.

2/3 + 2/3 = 4/6 Hope this helps!

2/3 written with a denominator  of 6 is 4/6 simply found by multiplying the whole fraction by 2

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)