Question

Adding and subtracting polynomials.

(6-t-t^4) + (9t+t^4)

How do you solve this problem?

Answer 1

just collect terms with the same power and then simplify:

6-t-t^4 + 9t+t^4
= (-1+1)t^4 + (-1+9)t + 6
= 8t+6

It is customary to list the highest power first, and then descend. Notice how the t^4 terms vanish because -1+1 = 0

Answer 2

where did the -1 and the +1 come from?