(4x+y)+5
20x+5y
20x+5y+0
third term is zero
5x+34=-2(1-7x)
Steps:
5x+34=-2+14x
5x+34-14x= -2
-9x + 34= -2
-9x = -2-34
-9x = -36
X= -36/-9
Answer: x= 4
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