Answer:
Step-by-step explanation:
Let's denote the number we are looking for as "n".
According to the given conditions:
- Add "n" to the numerator of 7/8: this becomes (7 + n)/8
- Add "2n" to the denominator of 7/8: this becomes 7/(8 + 2n)
Now, the result is 8/13:
(7 + n)/(8 + 2n) = 8/13
To solve for "n", we need to cross multiply:
13(7 + n) = 8(8 + 2n)
91 + 13n = 64 + 16n
Rearranging the equation:
3n = -27
n = -9
Therefore, the number we were looking for is -9.