Question

If C = 2m2 + m and D = 2 – 6m + 2m², find an expression that equals 2C - 2D in standard form.

Answer 1

C = 2m^2 + m
D = 2 - 6m + 2m^2

2C = 2(2m^2 + m) = 4m^2+2m
2D = 2(2-6m+2m^2) = 4-12m+4m^2

2C - 2D =
4m^2+2m-(4-12m+4m^2) =
4m^2+2m-4+12m-4m^2 =
0m^2 + 14m -4 =
14m - 4