Question

Help answer and EXPLAIN STEP BY STEP

Answer 1

15. $(-k^{3} -5k^{2} + 1) - (6k^{3}-k^{2} -2)$

Step 1: Distribute the subtraction sign to all the numbers in the second set of parentheses...

$(-k^{3} -5k^{2} + 1) - (6k^{3}-k^{2} -2)$

$-k^{3} -5k^{2} +1 - 6k^{3} +k^{2} +2$

Step 2: Combine like terms ($k^{2}$'s go with $k^{2}$'s)

$-k^{3} -5k^{2} + 1 - 6k^{3}+k^{2} +2$

$-5k^{2} +k^{2}$

$-4k^{2}$

$-k^{3} -4k^{2} + 1 - 6k^{3}+2$

Step 3: Combine like terms ($k^{3}$'s go with $k^{3}$'s)

$-k^{3} -4k^{2} + 1 - 6k^{3}+2$

$-k^{3} + (- 6k^{3})$

$-7k^{3}$

$-7k^{3} -4k^{2} + 1 +2$

Step 4: Combine like terms (normal numbers go with normal numbers)

$-7k^{3} -4k^{2} + 1 +2$

1 + 2

3

$-7k^{3} -4k^{2} + 3$

You were correct!

16. $49m^2 - 84mn + 36n^2$

I don't really know how to explain this one but I got: (7m-6n)(7m-6n)