Answer:
The two polynomial CAN be
and
.
Step-by-step explanation:
Step 1: <u>Simplify the expression:</u>



Step 2: <u>Think of a random polynomial:</u>

Step 3: <u>Either add your "random polynomial" by </u>
<u> or subtract it.</u>
<u>I want to add it so...</u>

= 
Check by subtracting
and
.

- 
_____________________
<em><u>or </u></em>
<em><u /></em>
Answer:
-3mn
Step-by-step explanation:
It seems you might be missing some of the question, as you haven't given what m and n are equal to.
If the question has just given you x, then you would simply just simplify it to get -3mn.
If the question is 5m^2 the answer is 80. And if the question is 5m2 then it is 40