That statement is true, since the ratios are equivalent, they are equal.
6 + 5 = 6 - (-5)
If you subtract a negative number from something, the two negatives cancel out.
(f+g-k)(x) means to add the equations f(x) and g(x) then subtract k(x)
2x^2 + 3x + 4x - 9 = 2x^2 +7x -9
2x^2 + 7x - 9 - x^2 -7x = x^2 -9
The answer is : x^2 - 9
The thingy became smaller..?.
