Answer:
not factorable
Step-by-step explanation:

The easiest way to factor is to find two numbers of the "a" value (the coefficient before
) and the factors of the c value (10) that ADD up to give you -9, in this case it would be:
1 -10 --> 1(-10) gives you -10
1 -1 --> 1(-1) gives you -1
adding these together -10 + (-1) = -11 which does not equal -9.
You could stop here and conclude that this is not factorable by inspection.
Another method: using the quadratic formula to find its roots.
Roots:
and 
Answer:
x = 25°
Step-by-step explanation:
2x-10°+2x-10°+100°=180°[sum of angles in a triangle ]
4x+80°=180°
4x=100°
x=25°
The correct answer is 74 because 3*26=78 and 78-4=74
72 is multiples of 3,9, and 12