The square of 1 - the square of 2 + the square of 3 - the square of 4 + the square of 5 - the square of 6 + +The square of 99

The square of 1 - the square of 2 + the square of 3 - the square of 4 + the square of 5 - the square of 6 + +The square of 99

1²-2²+3²-4²+5²-.+99²-100²+100²=(1²-2²)+(3²-4²)+(5²-6²)+.+99²-100²+100²=(1+2)(1-2)+(3+4)(3-4)+(5+6)(5-6)+.+(99+100)(...