(x+3)(x+3) = x^2 -3 + 3x
x^2 + 3x + 3x + 9 = x^2 + 3x - 3
x^2 + 6x + 9 = x^2 + 3x - 3
6x + 9 = 3x - 3
3x + 9 = -3
3x = -12
x = -4
Check:
(-4+3)^2 = (-4)^2 - 3(1+4)
(-1)^2 = 16 - 3(5)
1 = 16-15
1 = 1 :)
You see how many times 6 can fit into 13 (two), and see how many 6ths are left (one). So the answer would be 2 and 1/6.
