Marcie solved the following inequality, and her work is shown below:

−2(x − 5) − 12 ≤ 4 + 6(x + 3)
−2x + 10 − 12 ≤ 4 + 6x + 18
−2x − 2 ≤ 6x + 22
−8x ≤ 24
x ≤ −3

What mistake did Marcie make in solving the inequality?
She subtracted 6x from both sides when she should have added 2x.
She added 2 to both sides when she should have subtracted 22.
When dividing by −8, she did not change the ≤ to ≥.
She did not make a mistake.

Question

Marcie solved the following inequality, and her work is shown below:

−2(x − 5) − 12 ≤ 4 + 6(x + 3)
−2x + 10 − 12 ≤ 4 + 6x + 18
−2x − 2 ≤ 6x + 22
−8x ≤ 24
x ≤ −3

What mistake did Marcie make in solving the inequality?
 She subtracted 6x from both sides when she should have added 2x. 
She added 2 to both sides when she should have subtracted 22. 
When dividing by −8, she did not change the ≤ to ≥. 
She did not make a mistake.

jocelm · Answer

Doesn't look like she made a mistake to me.

maddyhall15 · Answer

This is correct.

tay1lynn · Answer

ok thank you so much

zzr0ck3r · Answer

When you divide or multiply by a negative you need to flip the inequality sign.

zzr0ck3r · Answer

@JoCelM  and @maddyhall15 and @tay1lynn

zzr0ck3r · Answer

$−8x ≤ 24\implies x\ge \dfrac{24}{-8}\implies x\ge -3$

zzr0ck3r · Answer

Understand?

tay1lynn · Answer

Yes I do now thank you

jocelm · Answer

Wow I didn't catch that! Good job.