Practicing Success
Find the product of (a + b + 2c)(a2 + b2 + 4c2 − ab − 2bc − 2ca). |
a3 + b3 + 8c3 − 2abc a3 + b3 + 8c3 − abc a3 + b3 + 6c3 − 6abc a3 + b3 + 8c3 − 6abc |
a3 + b3 + 8c3 − 6abc |
We know that, x3 + y3 + z3 – 3xyz = (x + y + z) (x2 + y2 + z2 – xy – yz – zx) (a + b + 2c) (a2 + b2 + 4c2 – ab – 2bc – 2ca) = a3 + b3 + 8c3 – 6abc |