Remove all the brackets
3(7 + 2x) + 3 = 3(5 + x) − 9(x + 1)
21 + 6x + 3 = 15 + 3x - 9x - 9 Collect like terms.
24 + 6x = 6 - 6x Add 6x to both sides.
24 + 6x + 6x = 6 Subtract 24 from both sides
12x = 6 - 24
12x = - 18 Divide by 12
x = - 18 /12
x = - 1.5
Check
3(7 + 2*(-1.5)) + 3 = ? 3(5 + -(1.5) - 9(-1.5 + 1)
3(7 - 3) + 3 =? 3(3.5) - 9*(-1/2)
3*4 + 3 =? 10.5 + 4.5
12 + 3 =? 15 And it checks.
