To simplify this expression, we can start to sum the like terms:
[tex]2x+7x-3-9=9x-12[/tex]We can also notice that both values have the 3 as a common factor, then:
[tex]9x-12=3\cdot(3x-4)[/tex]Therefore, the expression 2x -3 + 7x - 9 is equivalent to 9x - 12 = 3*(3x - 4).
We can use the two results as a simplification of the latter expression.
