Answer:
(-2x)-5x-9 = (-7x)-9
3x - 13 = 3x - 13 (you cannot simplify more)
Your question was wery wierd but i tried to answer best I could.
And also I dont know what you mean about "-+5"
A straight angle is 180 degrees. if you bisect it (cut it in half), you'll end up with two 90 degree angles, which are called right angles.
Yes because it is a whole number
