Question

Factorise 7a^3+56b^3

Answer 1

X^3+y^3=(x+y)(x^2-xy+y^2)

X^3+y^3=(x+y)(x^2-xy+y^2)7a^3+56b^3

X^3+y^3=(x+y)(x^2-xy+y^2)7a^3+56b^3=7(a^3+8b^3)

X^3+y^3=(x+y)(x^2-xy+y^2)7a^3+56b^3=7(a^3+8b^3)=7[a^3+(2b)^3]

X^3+y^3=(x+y)(x^2-xy+y^2)7a^3+56b^3=7(a^3+8b^3)=7[a^3+(2b)^3]=7(a+2b)[a^2-2ab+(2b)^2]

X^3+y^3=(x+y)(x^2-xy+y^2)7a^3+56b^3=7(a^3+8b^3)=7[a^3+(2b)^3]=7(a+2b)[a^2-2ab+(2b)^2]=7(a+2b)(a^2-2ab+4b^2)