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Math Help - Just a quick question...

  1. #1
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    Just a quick question...

    Can anyone check this over for me? I did something wrong, but I'm not sure what it is...

    Expand, Then simplify:

    3(2m-4n+3)-5(-2m+5n-1) --->(6m-12n+9)-(10m-25+5)

    (This is the part where I simplified)---> -4m-37n+5 (???)

    In the textbook, the correct answer is 16m-37n+14...help?
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by May_18 View Post
    Can anyone check this over for me? I did something wrong, but I'm not sure what it is...

    Expand, Then simplify:

    3(2m-4n+3)-5(-2m+5n-1) --->(6m-12n+9)-(10m-25+5)

    (This is the part where I simplified)---> -4m-37n+5 (???)

    In the textbook, the correct answer is 16m-37n+14...help?
    the line in red is wrong

    note you have a negative sign outside the brackets, which when expanded will give you a -10m for the first term. however, -5*-2m = +10m

    prevent this mistake form happening again: remove the brackets when you expand! that way, you can correctly see what terms should have what sign
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  3. #3
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    OH! *smacks self on forehead* How could I forget? Thank you very much for the help! I really appreciate it!
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