Question

How do we solve an equation by factoring?

Problems such as x² - 9 = 0 and x²  + 13x = -36.

Answer 1

`1.\\x^2-9=0\\ Using\ formula:\\ a^2-b^2=(a-b)(a+b)\\ x^2-9=0\\ x^2-3^2=0\\ (x-3)(x+3)=0\\\\ Asnwer:\ \ x^2-9=(x-3)(x+3)\\\\2.\\x^2+13x=-36\\ x^2+13x+36=0\\ Write\ 13x\ as\ 9x+4x\\x^2+9x+4x+36=0\\ x(x+4)+9(x+4)=0\\(x+4)(x+9)=0\\\\Answer:\ \ x^2+13x+36=(x+4)(x+9)`