Answer is x = -4
Arrange the equation so that +3 goes to the other side by subtracting -3 from both sides.
The equation then becomes 9x = -36
Afterwards, to separate the 9 from the x, you divide 9 on both sides.
The equation then becomes x = -36/9, where -36 divided by 9 is -4.
The equation is then left with x = -4 where you have solved x.
Hope this helps!