Jawabanmu

2014-09-07T23:03:07+07:00
1) a. 5a-2a+7b+b
=3a+8b

b. 12a+9-8a-12
=12a-8a+9-12
=4a-3

2) 12x^2-8xy -(-6x^2-15xy)
12x^2-8xy+6x^2+15xy
12x^2+6x^2-8xy+15xy
18x^2+7xy

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