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If the answer is 1-2/3m what is the question>

How can you solve equations like these?

9r + 7 = 4r - 8

Need to get the r on one side.
1st- subtract 4r from the right side of the = sign. What you do to one side do to the other. 9r-4r+7=4r-4r-8. 5r+7=-8
2nd- subtract 7 from the left side to get r's by themselves. 5r+7-7=-8-7....5r=-15.
Divide 5r by 5.....remeber do it to both sides......5r/5=-15/5......r=-3
check answer.
9(-3)+7=4(-3)-8....-27+7=-12-8............-20=-20


Thanks for your help. I'm completely lost. Can you explain how 9r+7 = 4r-8?

  • math -

    r=-3

  • math -

    4.9u+5.87=23.81

  • math -

    what is rule for input value of n?

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