Simplify the following expression. (7.8x + 8.7) - (-4.34x + 3.16)

7.8x + 8.7 - (-4.34x + 3.16)

7.8x + 8.7 + 4.34x - 3.16

Combine like terms:

(7.8x + 4.34x) + (8.7 - 3.16)

12.14x + 5.54