Question

Subtract the following polynomials. Write answer in a-b-c-d order. From 4a+7b-12c subtract 8a-9b+12d

Answer 1

$(4a+7b-12c)-(8a-9b+12d)\\4a+7b-12c-8a+9b-12d$

Negative multiply negative = Positive

Negative multiply positive = negative

$-8a+4a+9b+7b-12c-12d\\-4a+16b-12c-12d$

Thus the answer is -4a + 16b - 12c - 12d.