Factorise x^2 - 7x + 12 = 0

Method 1) Find two numbers which multiply to 12, and who’s sum is -7. ( This could be done by writing out the factors of 12, and seeing which add to -7.) From doing this we get -3 and -4, therefore our answer is (x-3)(x-4).Method 2) Use the quadratic formula where a=1, b=-7, c=12 to find the two values of x (3 and 4), giving the factors (x-3) and (x-4).