Question

What value of x is in the solution set of 9(2x + 1) < 9x – 18?

Answer 1

-3 > x

Explanation:

1. Multiply 2x and 1 by 9. You have 18x + 9 < 9x - 18.
2. Add 18 to 9. You are adding because it is the opposite of subtraction, so it cancels out. You now have 18x + 27 < 9x.
3. Subtract 18x from 9. There is no addition sign in front of the 18x, but it's basically implied. You now have 27 < -9x.
4. Divide both sides by -9. When you divide by a negative, the inequality sign flips. You now have -3 > x.