3 = 3/4(b - 8)
Switch sides
3/4(b - 8) = 3
Next, multiply both sides by 4
4 * 3/4(b - 8) = 3 * 4
Then simplify,
3(b - 8) = 12
Next, divide both sides by 3
3(b - 8)/3 = 12/3
Then, simplify
b - 8 = 4
Then, add 8 to both sides
b - 8 + 8 = 4 + 8
Simplify, b = 12