You first simplify the expression using PEMDAS
-2x^3-10x^2+2x^3-10x^2+x
then combine like terms,
(-2x^3+2x^3), (-10x^2-10x^2), x
cancels out^
so the answer would be -20x^2+x
        
             
        
        
        
Obtuse angles are over 90 degrees but less than 180 degrees. So minimum y can be is 10: (5 x 10) + 45 = 95 degrees (which is more than 90). Maximum for y is 26: (5 x 26) + 45 = 175 (which is less than 180 degrees)
 
        
             
        
        
        
Answer:
C. They are the same line. 
Step-by-step explanation:
In order to compare the linear equations given, they need to be in the same form.  The best form in order to evaluate slope and y-intercept is slope-intercept form, y = mx + b.  Since the second equation is already in slope-intercept form, we need to use inverse operations to convert the first equation: 
6x - 2y = 16 ----  6x - 2y - 6x = 16 - 6x ----  -2y = -6x + 16 
-2y/-2 = -6x/-2 + 16/-2
y = 3x - 8
Since both equations are in the form y = 3x - 8, then they are both the same line.