Practicing Success
What is the value of $(a^2 +b^2 +4c^2 -ab -2ca)( a + b + 2c) ?$ |
$a^3 + b^3 +8c^3 - 8abc $ $a^3 + b^3 +8c^3 - 4abc $ $4a^3 + b^3 +8c^3 - 9abc $ $a^3 + b^3 +8c^3 - 6abc $ |
$a^3 + b^3 +8c^3 - 6abc $ |
We know, 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 |