Question

2+3=8,
3+7=27,
4+5=32,
5+8=60,
6+7=72,
7+8=??

Answer 1

98

2+3=2*[3+(2-1)]=8

3+7=3*[7+(3-1)]=27

4+5=4*[5+(4-1)]=32

5+8=5*[8+(5-1)]=60

6+7=6*[7+(6-1)]=72

therefore

7+8=7*[8+(7-1)]=98

x+y=x[y+(x-1)]=x^2+xy-x