Question

Step 1: 7x + 5 > 4x + 2 (Given)
Step 2: 3x + 5 > 2 (Subtraction)
Step 3: 3x > 3 (Subtraction)
Step 4: x > 1 (Division)
Zareen is trying to find her mistake in the problem shown. In which step(s) did she make her mistake?

Answer 1

Answer: Step 3: $3x>3$ (Subtraction).

Step-by-step explanation:

1- Given the inequality shown in the problem, Zareen should solve it as following:

2-Subtract 4x from both sides:

$7x + 5-4x > 4x + 2 -4x\\3x+5>2$

(Zareen did this step correctly)

3- Subtract 5 from both sides:

$3x + 5-5 > 2-5\\3x>-3$

(As you can see, Zareen made a mistake in Step 3, because the subtraction is actually  $2-5=-3$)

4- Divide both sides by 3, then:

$\frac{3x}{3}>\frac{-3}{3}\\\\x>-1$