Let's say x to the shoter piece's length, since the longer one is 13 in longer, it's length has to be x+13 in. We know the sum of these pieces is equal to 47. So let's solve:
\(x+x+13=47\\ 2x+13=47\\ 2x=47-13\\ 2x=34\\ x=\frac { 34 }{ 2 } \\ x=17\)
the shorter piece's length 'x' is 17 , so the longer piece's length 'x+13' is : \(x+13\\ 17+13=30\)
