Answer:
x = 42
Step-by-step explanation:
1 - (2x + 9) = 4(21 - 2)
Distributive property ( multiply whatever is in the parenthesis by (-) for the first one, and (4) for the second one)
1 - * 2x + - * 9 = 4 * 21 - 4 * 2
1 - 2x - 9 = 84 - 8
Combine like terms
-8 - 2x = 76
Add 8 on both sides
-8 + 8 - 2x = 76 + 8
2x = 84
Divide by 2 on both sides to isolate the variable
2x/2 = 84/2
x = 42
Hope this helped!
Have a supercalifragilisticexpialidocious day!