Which expression is equivalent to 9x – 2x2 + 4x – x?

Simonne used the following steps to simplify the given expression. 12 - 3(-2x + 4) step 1: 12 + (–3)·(–2x) + (–3)·(4) step 2: 12 + 6x + (–12) step 3: 12 + (–12) + 6x step 4: 0 + 6x step 5: 6x what property of real numbers was used to transition from step 3 to step 4? a. identity property of addition b. inverse property of addition c. associative property of addition d. commutative property of addition

Simplify. 4+3/7x-2-2/7x a. 2-5/7x b. 6-1/7x c. 2+1/7x d. 6+5/7x

For which pairs of functions is (f•g)(x)=12x? f(x)=3-4x and g(x)=16x-3 f(x)=6x2 and g(x)= 2/x f(x)= and g(x) = 144x f(x)=4x and g(x) =3x