2(x - 3) + 9 = 3(x + 1) + x
First distribute 2 to both x and -3, and 3 to both x and 1
2(x) = 2x
2(-3) = -6
3(x) = 3x
3(1) = 3
2x - 6 + 9 = 3x + 3 + x
Simplify
2x + 3 = 4x + 3
Isolate the x. Note the equal sign. What you do to one side, you do to the other. Subtract 4x from both sides, and 3 from both sides
2x (-4x) + 3 (-3) = 4x (-4x) + 3 (-3)
2x - 4x = 3 - 3
-2x = 0
Isolate the x, divide -2 from both sides
-2x/-2 = 0/-2
x = 0/-2
x = 0
0 is your answer for x
hope this helps
