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Answer:
15a -9ab + 2b - 15
Step-by-step explanation:
12a - 9ab + 5b - 3 -( 4a -7a + 3b + 12)
12a - 9ab + 5b -3 -4a + 7a - 3b - 12
15a -9ab + 2b - 15
Step 1:
align the variables
Step 2:
find the sum
[tex]4a-7ab+3b+12\\12a-9ab+5b-3\\---------\\16a-16ab+6b+9[/tex]
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