=(2+3.15+5.87)*(3.15+5.87)+(2+3.15+5.87)*7.32-(2+3.15+5.87)*(3.15+5.87)-7.32*(3.15+5.87)
=7.32*(2+3.15+5.87-3.15-5.87)
=7.32*2
=14.64
(2+3.15+5.87)*(3.15+5.87+7.32)-(2+3.15+5.87+7.32)*(3.15+5.87)
=[(2+3.15+5.87)*(3.15+5.87)+(2+3.15+5.87)*7.32]-[(2+3.15+5.87)+(3.15+5.87)+(3.15+5.87)*7.32]
=0+(2+3.15+5.87)*7.32-(3.15+5.87)*7.32
=2*7.32
=14.64