15. [tex](-k^{3} -5k^{2} + 1) - (6k^{3}-k^{2} -2)[/tex]
Step 1: Distribute the subtraction sign to all the numbers in the second set of parentheses...
[tex](-k^{3} -5k^{2} + 1) - (6k^{3}-k^{2} -2)[/tex]
[tex]-k^{3} -5k^{2} +1 - 6k^{3} +k^{2} +2[/tex]
Step 2: Combine like terms ([tex]k^{2}[/tex]'s go with [tex]k^{2}[/tex]'s)
[tex]-k^{3} -5k^{2} + 1 - 6k^{3}+k^{2} +2[/tex]
[tex]-5k^{2} +k^{2}[/tex]
[tex]-4k^{2}[/tex]
[tex]-k^{3} -4k^{2} + 1 - 6k^{3}+2[/tex]
Step 3: Combine like terms ([tex]k^{3}[/tex]'s go with [tex]k^{3}[/tex]'s)
[tex]-k^{3} -4k^{2} + 1 - 6k^{3}+2[/tex]
[tex]-k^{3} + (- 6k^{3})[/tex]
[tex]-7k^{3}[/tex]
[tex]-7k^{3} -4k^{2} + 1 +2[/tex]
Step 4: Combine like terms (normal numbers go with normal numbers)
[tex]-7k^{3} -4k^{2} + 1 +2[/tex]
1 + 2
3
[tex] -7k^{3} -4k^{2} + 3[/tex]
You were correct!
16. [tex]49m^2 - 84mn + 36n^2[/tex]
I don't really know how to explain this one but I got: (7m-6n)(7m-6n)
