(0.5x + 7) - (1.2x - 3)
= (0.5x + 7) -1(1.2x - 3)
= 0.5x + 7 - 1.2x + 3
= (Now, we will combine and group the like terms.)
= 0.5x - 1.2x + 7 + 3
= -0.7x + 10
So, in conclusion, the answer to this question is: -0.7x + 10 which is equal to the third expression: (0.5x+(-1.2x))+(7+3).
Glad I could help!