1/(x+3) = 7/(4x+12) - 2
1/(x+3) = 7/(4(x+3)) - 2
1/z = 7/(4z) - 2 ..... let z = x+3
4z*[1/z] = 4z*[7/(4z) - 2]
4 = 7 - 8z
4-7 = 7 - 8z - 7
-3 = -8z
-8z = -3
-8z/(-8) = -3/(-8)
z = 3/8
x+3 = 3/8 .... replace z with x+3
x+3-3 = 3/8 - 3
x = 3/8 - 24/8
x = (3-24)/8
x = -21/8
The final answer, as a fraction, is x = -21/8
If you want the answer in decimal form, then using a calculator we can say -21/8 = -2.625