10 = ax - 3b
First, add 3b to both sides. / Your problem should look like: 10 + 3b = ax.
Second, divide both sides by a. / Your problem should look like: [tex] \frac{10 + 3b}{a} [/tex] = x.
Third, switch sides. / Your problem should look like: x = [tex] \frac{10 + 3b}{a} [/tex] which is your answer.