1. 12a-5b+7a-8b= 2. 3(2x5y)+4(2x5y)=

1. 12a-5b+7a-8b
= 12a+7a-5b-8b
= 19a + 3b
2. 3(2.5y) + 4(2.5y)
= (3.2) + (3.5y) + (4.2) + (4.5y)
= 6+15y+8+20y
= 15y+20y+6+8
= 35y+14


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