Question

Solving Inequalities
Which work correctly uses properties of inequality to find the solution to –0.4x – 10 > 14?

–0.4x – 10 > 14
–0.4x > 4
x > –10
–0.4x – 10 > 14
–0.4x > 24
x > –60
–0.4x – 10 > 14
–0.4x > 4
x < –10
–0.4x – 10 > 14
–0.4x > 24
x < –60

Answer 1

The correct work is the fourth:

-0.4x - 10 > 14
⇒ -0.4x > 24 (add 10 to both sides)
⇒ x < -60 (divide by -0.4 and reverse the inequality because you divided by a negative)

So the solution is x < -60.