Question 105097
	

{{{x3 – 7x2 + 9x - 63}}} group {{{1st}}} with {{{3rd}}} term, and {{{2nd}}} with {{{4th}}} term

{{{( x^3 + 9x) - (7x^2 + 63)}}}

{{{x(x^2 + 9) - 7(x^2 + 9)}}}

{{{(x^2 + 9)( x - 7)}}}    here, number {{{9}}} you can write as {{{3^2}}}

{{{(x^2 + 3^2)(x - 7)}}}  now factor {{{x^2 + 3^2}}} as {{{(x-3)(x+3)}}}

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