Set the two expressions equal to each other.
7x + 3 = 9x
Simplify, isolate the x, subtract 7x from both sides
7x (-7x) + 3 = 9x (-7x)
3 = 2x
Set the equation = 0, subtract 3 from both sides
3 (-3) = 2x (-3)
0 = 2x - 3
2x - 3, or D, should be your answer
hope this helps
