The answer is -7.20 click on file for more details.
7/8 + 4/8= 11/8 so 11/8 ÷2 = 5.5/8 she puts 5 1/2 /8 cups of the mixture in each bowl
This equation uses two properties of logarithms:


So you could take the ln from left and right hand side in the equation, and get:
(2-x)ln 3 = x ln 5
then
2 ln 3 - x ln 3 - x ln 5 = 0 =>
x(ln 3 + ln 5) = 2 ln 3
so x = 2 ln 3 / (ln3 + ln5)
Now using the 1st property you can say 2 ln 3 is ln 3² = ln9
and using the 2nd property you can say ln3 + ln5 = ln15
so x= ln9 / ln15
Answer:
129 - 280 = 51.. So the answer is 51%