Answer:
The answer is A
Step-by-step explanation:
 
        
             
        
        
        
Answer:
a = 4
Step-by-step explanation:
y = 2x + 1 ......(1)
Going through y - y1 = m(x - x1)
m is slope and it is 2
y1 = 9 and x1 = a
y - 9 = 2(x - a)
y - 9 = 2x - 2a
y = 2x - 2a + 9 ........(2)
Equating (1) and (2)
2x + 1 = 2x - 2a + 9
Collecting like terms
2x - 2x + 2a = 9 - 1
2a = 8
a = 8/2
a = 4
 
        
             
        
        
        
-3...idk what your asking...but on a number line, 3 places to the left of zero is negative three
        
             
        
        
        
Answer:
7) 49°
8) 77°
9) 87°
10) 135°
Step-by-step explanation:
7) The angles are between the parallel lines, so are "interior." They are on opposite sides of the transversal, so are "opposite interior" angles. Such angles are congruent, so ...
... ? ≅ 49°
8) The angles are adjacent interior angles, so are supplementary. 
... ? + 103° = 180°
... ? = 77°
9) The angles are outside the parallel lines, so are "exterior." They are on opposite sides of the transversal, so are "opposite exterior" angles. Such angles are congruent.
... ? ≅ 87°
10) These are vertical angles, so are congruent. (The other parallel line is irrelevant and doesn't need to be there for this relationship to be true.)
... ? ≅ 135°