3.2 - 9x + 7.1 -3x
We need to combine like terms. Like terms are the values that have the same variable. So 9x and 3x are like terms, and 3.2 and 7.1 are also like terms.
So we can reorder the qeustion to:
3.2 + 7.1 -9x - 3x
Now we just simplify this, and it becomes:
10.3 - 9x - 3x
To simplify -9x -3x we can simply ignore the variable do the subtraction and bring back the variable:
-9x -3x = -9 - 3 = -12 = -12x
Another way to visualize it is if we take x as a factor, so:
-9x-3x = x(-9-3) = x(-12) = -12x
So anyways, our final answer will be:
3.2 - 9x + 7.1 - 3x = 10.3 - 12x