Question

Mr. McGill is solving the following problem: -2x < 10. He divides both sides by -2 and gets x < -5 as his answer. What error did Mr. McGill make and what should the correct answer be?

Answer 1

see explanation

Step-by-step explanation:

Consider the following true statement

- 4 > - 8 ( divide both sides by - 2 )

2 > 4 ← false statement

To make the statement true, we must reverse the symbol , that is

2 < 4

When multiplying or dividing by a negative value , reverse the symbol.

Then correct answer is

- 2x < 10

divide both sides by - 2, reversing the symbol as a result of dividing by a negative value.

x > - 5 ← is the correct answer

Answer 2

Mr. McGill incorrectly solved the inequality by not flipping the sign when dividing by a negative number, resulting
`in x > -5` as the correct answer.

Step-by-step explanation:

Mr. McGill made an error while solving the inequality
`-2x < 10`.

The mistake lies in not reversing the inequality sign after dividing both sides by a negative number.

When dividing or multiplying an inequality by a negative number, the inequality sign must be flipped.

Thus, the correct step is to divide both sides by
`-2`, resulting in
`x > -5`, not
`x < -5`.