Question

Sam solved the following problem:

-4x + 5 > 29
-4x + 5 - 5 > 29 - 5
-4x > -24
-4x/-4 > -24/-4
x > 6

What were his two mistakes?

Answer 1

-4x > 24

x< 6

Explanation:

-4x + 5 > 29

-4x + 5 - 5 > 29 - 5 (subtracted 5 on both sides)

To remove +5, Sam subtracted 5 on both sides. but 29-5 is 24

we always put the sign of greatest number . so its positive

-4x > 24 is correct

-4x/-4 > 24/-4

Dividing both sides by -4 is correct. But when we divide by negative number we need to flip the inequality sign . so > becomes <

x < 6