Question

Solve the following:
(i) (a -3b)^3 + (a + 3b)^3​

Answer 1

ANSWER:

WE NEED A FACTOR THAT MAKES OUR EXPRESSION ZERO WHEN IT IS ZERO

IF (a, b, c) IS THE FACTOR, THEN F (a, b, c) =0

LETS EXPRESS a FOR F (a, b, c) =0

a= g (b, c)

g (b, c) 3+b3+c3–3g (b, c) bc = 0.

−b3−c3−3bc2−3b2c+x (SOMETHING) +b3+c3+3bc2+3b2c+x (OTHER THING)

=x( AN EXPRESSION )

SO NOW WE KNOW THAT a= −b−c  WILL MAKE IT 0

ONE OF ITS FACTOR IS  (a+b+c)

NOW DIVIDE THE EXPRESSION

a3+b3+c3−3abc= (a+b+c) (a2+b2+c2−ab−ac−bc)

THANK YOU