Question

15) Describe what is wrong with this solution (there could be numerous mistakes):I-4x + 1I > 3- 4x + 1 > 3- 4x > 4x < - 1-4x + 1 > - 3- 4x > 2x < 1/2

Answer 1

For the first solution, the error is adding 1 to 3 to get 4 instead of subtracting 1 from 3 to get 2.

It should have been

I-4x + 1I > 3

- 4x + 1 > 3

- 4x > 3 - 1

- 4x > 2

x < - 2/4

x < - 1/2

For the second solution, the error was omitting the negative sign in the final answer. It should have been

-4x + 1 > - 3

- 4x > 2

x < -1/2