I'm stuck on this question, and really need help.
Question: True or false? Explain your answer.
The inequality −2(x + 10) ≥ 75 says the same thing as −2x − 20 ≥ 75. I can multiply by -2 on the left side without reversing the inequality symbol.
Answer: True. You are distributing the -2 in the parenthesis.
If anyone has anything to add to it, please do (I'm not sure if this is the complete answer.)
4 answers
I agree
False. Multiplying by negative values reverses the direction. It is really just a shorthand way of swapping sides.
-2x-20 >= 75
add 2x to get
-20 >= 75+2x
subtract 75
-95 >= 2x
Now the 2x is on the small side of the inequality, so it's the same as
2x <= -95
-2x-20 >= 75
add 2x to get
-20 >= 75+2x
subtract 75
-95 >= 2x
Now the 2x is on the small side of the inequality, so it's the same as
2x <= -95
Oops. I read ahead. You (and of course, Reiny!) are correct
Thank you guys so much, I appreciate the help!