There is a combination of brackets and an equals sign that may be confusing on our end as to if we distribute the -18 to the terms inside the brackets (thereby ignoring the equals signs) or solve for x because there is an equals sign (thereby ignoring the brackets) so I will do both below.
First, with distributing the -18
7x + 3x - 18(6x + 3)
Combine like terms
10x - 18(6x + 3)
Now distribute the -18 to the terms within the parentheses or brackets (they serve the same function in this equation).
10x - 18(6x) - 18(3)
10x - 108x - 54
Combine like terms
-98x - 54
-2(49x + 27)
Now, with using the equals sign
7x + 3x - 18 = 6x + 3
Combine like terms
10x - 18 = 6x + 3
Add 18 to both sides and subtract 6x from both sides to get variables on the left of the equals sign and constants on the right.
10x - 6x - 18 + 18 = 6x - 6x + 3 + 18
Combine like terms
4x + 0 = 21 + 0
Simplify
4x = 21
Divide both sides by 4 to isolate variable x
4x / 4 = 21 / 4
x = 21/4
x = 5.25 or
