What should be subtracted from 2a+8b+10 to get -3a+7b+16?

Let k should be subtracted


2a + 8b + 10 - k = -3a + 7b + 16


Then,


k = 2a + 8b + 10 - ( -3a + 7b + 16)


k = 2a + 8b + 10 + 3a - 7b - 16


k = 5a + b - 6


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