x13 − x23 | |
= | |
x12 − x22 |
(x1 −x2)*(x12 + x1*x2 + x22) | ||
= | = | |
(x1 −x2)*(x1 + x2) |
x12 + x1*x2 + x22 | ||
= | = | |
x1 + x2 |
( x1 + x2)2 −2 x1*x2 +x1*x2 | ||
= | = | |
x1 + x2 |
( x1 + x2)2 − x1*x2 | ||
= | ||
x1 + x2 |
x13−x23 | ||
x12−x22 |
(x1−x2(x12+x1x2+x22) | ||
= | ||
(x1−x2)(x1+x2) |
[(x1+x2)2−x1x2] | ||
= | ||
x1+x2 |