7 + 8 = ?

If:

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

then:

7 + 8 = ?





Answer:

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"