Answer:
x= 12
Step-by-step explanation:
Simplifying
7x + 21 = 105
Reorder the terms:
21 + 7x = 105
Solving
21 + 7x = 105
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-21' to each side of the equation.
21 + -21 + 7x = 105 + -21
Combine like terms: 21 + -21 = 0
0 + 7x = 105 + -21
7x = 105 + -21
Combine like terms: 105 + -21 = 84
7x = 84
Divide each side by '7'.
x = 12
Simplifying
x = 12
