Question

130% of the sum of 7 and a number n is equal to 91.

Answer 1

$1.3(7+n)=91|:1.3\\7+n=70|-7\\ n=63$

Answer 2

$130\%(7+n)=91 \\ 1.3(7+n)=91 \\ 7+n=\frac{91}{1.3} \\ 7+n=70 \\ n=70-7 \\ n=63$