Answer:
x = 26
Explanation:
Before we begin, we must first remember that to solve for x, we have to get the variable (x) by itself.
To start, you would first subtract 12 from the left and right side of the equation.
3x + 12 - (12) = 90 - (12)
The 12 would cancel out on the left side (12 - 12 = 0) and you would now be left with 3x = 78.
Next, you would divide the left and ride side by 3.
3x ÷ 3 = 78 ÷ 3
This gives you the answer of 1x = 26 or x = 26