Question

87^2+73^2-27^2-13^2

Answer 1

87^2+73^2-27^2-13^2

=(87+73-27-13)^2

=120^2

=14400

Answer 2

\(87^2+73^2-27^2-13^2=\left(87^2-27^2\right)+\left(73^2-13^2\right)\)

              \(=\left(87-27\right)\left(87+27\right)+\left(73-13\right)\left(73+13\right)\)

\(=60\cdot114+60\cdot86=60\left(114+86\right)=60\cdot200=12000\)