So if we add-- let me write this on the left hand side-- so 10x squared plus 12x plus 20, over x minus 2 times x squared plus 2x plus 4, is equal to-- if we add these two things, we want to get a common denominator, which is x minus 2 times x squared plus 2x plus 4, just multiply the two things, and that'll be, when we add the common denominator, then it's a times this, x squared plus 2x plus 4, plus bx plus c, times this, times x minus 2.