Eduardo solved the following inequality and his work is shown below:

−5(x + 4) + 21 ≥ −3 + 4(x − 8)
−5x − 20 + 21 ≥ −3 + 4x − 32
−5x + 1 ≥ 4x − 35
−9x ≥ −36
x ≥ 1

What mistake did Eduardo make in solving the inequality?

When dividing by −9, he did not change the ≥ to ≤.
He subtracted 4x from both sides when he should have added 5x.
He subtracted 1 from both sides when he should have added 36.
He did not make a mistake.

Question

Eduardo solved the following inequality and his work is shown below:

−5(x + 4) + 21 ≥ −3 + 4(x − 8)
−5x − 20 + 21 ≥ −3 + 4x − 32
−5x + 1 ≥ 4x − 35
−9x ≥ −36
x ≥ 1

What mistake did Eduardo make in solving the inequality?

When dividing by −9, he did not change the ≥ to ≤.
He subtracted 4x from both sides when he should have added 5x.
He subtracted 1 from both sides when he should have added 36.
He did not make a mistake.

anonymous · Answer

-36/-4 is 9

anonymous · Answer

I know that but that doesnt really tell me anything..

anonymous · Answer

Florida dont think im being rude but why not trying to work the problem backwards? Thats what i do...

anonymous · Answer

How would u do that stuff backwards @lolrocker1

anonymous · Answer

Eduardo goofed up in the second last and last step

anonymous · Answer

-36/-9=4 not 1

texaschic101 · Answer

when dividing by a negative 9, he did not change the >= to <=. He also divided wrong, as UditKulka said...-36/-9 = 4