Answer:  54 mph
Step-by-step explanation:
d-the distance
s+9  -  the speed to the conference
d=6*(s+9)
s- is the speed on the way back home
d=7*s
so    6*(s+9)=7*s
        6s+54=7s
      -6s          -6s
        54= 7s-6s
        s=54  mph
 
        
             
        
        
        
Angles are always congruent
        
             
        
        
        
Answer:
EF=4
Step-by-step explanation:
vì diện tích bằng nhau và bằng 28 áp dụng công thức tính diện tích 
 
        
             
        
        
        
In order to determine the value of x, consider that one of the interior angles of the triangle is given by:
180 - (4x - 18) 
= 180 - 4x + 18
= 198 - 4x
Next, consider that the sum of the interioir angles of a triangle is equal to 180:
(2x + 6) + 36 + (198 - 4x)
= 2x + 6 + 36 + 198 - 4x
= -2x + 240 
this is equal to 180:
-2x + 240 = 180
-2x = 180 - 240
-2x = -60
x = 60/2
x = 30
Hence, the value of x is x = 30
 
        
             
        
        
        
Answer:
10.
bag a is lighter than bag b
bag b is lighter than bag c
so bag a is lighter that bag c
Step-by-step explanation:
... sorry i dont know #11, but hope this helps