HELP please, three questions, giving medal!

Question

anonymous · Answer

Question 5 (Multiple Choice Worth 1 points)

(07.02)

Which of the following shows that polynomials are closed under addition when two polynomials 4x2 − 8x − 7 and −5x + 16 are added?

 4x2 − 13x + 9 may or may not be a polynomial

 4x2 + 13x − 23 may or may not be a polynomial

 4x2 − 13x + 9 will be a polynomial

 4x2 + 13x − 23 will be a polynomial

Question 6 (Multiple Choice Worth 1 points)

(07.02)

Simplify: (5x2 + 3x + 4) + (5x2 + 5x - 1)

 10x2 + 8x + 5

 25x2 + 8x + 3

 10x2 + 8x + 3

 10x2 + 8x - 3

Question 7 (Multiple Choice Worth 1 points)

(07.02)

Simplify: (3x - 5) - (4x + 6)

 -x + 11

 x + 11

 -x -11

 x - 11

yanasidlinskiy · Answer

The last one would be -x-11.|dw:1398442464460:dw|

anonymous · Answer

i will help you

yanasidlinskiy · Answer

|dw:1398542661586:dw|