1. D
2. E
3. B
4. Pentagon
5. C
Second side= x
First side = 2x
Third side = x+5
x+2x+x+5=49
4x=44
x=11
1st side= 22
2nd side = 11
3rd side = 16
I'm assuming you mean to list the terms of the expression. Those are mn, -2n, and +8. There are 3 terms there.
We have the equation:

so:

and:

This equation has one solution.
30 quarters because you times 6 by 5 and that equals 30 than you divine that by 4 and that 7.5