Question

factorise 8(x-3)³+343
Please solve it step by step​

Answer 1

Answer:

8(x-3)^3 + 343=

{2(x-3)}^3 + (7)^3

(2x - 6)^3 + 7^3

It is in a^3 + b^3 form = (a+b)(a^2+b^2 - ab)

(2x -6 + 7){(2x-6)^2 +7^2- (2x-6)7}

((2x+1)(4x^2 + 36 -24x + 49 -14x +42)

(2x+1)(4x^2 - 38x + 127)

since power is three, there should be three factors.

one factor is 2x + 1, other two factors will be imaginary because 38^2 is less than 4×4×127