How can you simplity x^2+2x-35/x^2+4x-21?
Divide the numerator and denominator by (x-21)
Divide the numerator and denominator by (x+7).
Divide the numerator and denominator by (x-3)
Divide the numerator and denominator by (x - 5)
Factor the numerator(x+7)(x-5). Then factor the denominator(x+7)(x-3). The x+7 in the top and bottom cancel. So you are left with x-5 in the numerator and x-3 in the denominator.
