Answer:
you can use similar triangle to make known degrees in problems to make then easier to solve. With similar triangle, the angles are the same, but the scale is different. So by using this, one can solve both at the same time, and just just scale up the smaller one or scale down the larger, by the given/found scale. 
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
the top one 
Step-by-step explanation:
just look at the y intercept, and if it has (0,2) its right 
and look also look at if it is going up from left to right or going down, beucase this has a negative slope it should be going down 
 
        
             
        
        
        
Answer:
c
Step-by-step explanation:
 
        
             
        
        
        
Answer:
x=2, or x=1
Step-by-step explanation:
Given the equations as 
f(x)=2x  and
g(x)=2^x
Using a graph tool the equations will intersect at points (2,4) and (1,2)
x =2 or x=1
 
        
             
        
        
        
Answer:
40:80
Step-by-step explanation:
x+2x=3x
3x=120
120/3=
40
40*2=80
40:80=1:2