I need help with a couple of math problems.

subtract 5m^2+2m+9 from 7m^2-5m-8

simplify (m^4)^3(m^2)^9/(m^3)^2

2 answers

7m^2 -5m -8
5m^2 +2m +9
__________
2m^2 -7m -17

Just line up subtract the columns with different powers of m

(m^4)^3 (m^2)^9
______________
(m^3)^2

= m^12*m^18/m^6
= m^30/m^6

= ?

Just use the rules
x^a * x^b = x^(a+b)
x^a/x^b = x^(a-b)
(x^a)^b = x^(ab)
-1(m-4)2m=8