# algebra

posted by on .

1. a number increased by 21 is 28. find the number

2. a number decreased by 12 is equal to 30. find the number.

3. 8 less than a number is 15. fid the number

• algebra - ,

Let x = the unknown number.

x + 21 = 28
x + 21 - 21 = 28 - 21
x = 7

x - 12 = 30
x = ?

How do you think you should set up the third problem?
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