C i believe because 180 is the overall degree and 50+28=78 and 180-78=102
Answer:



Step-by-step explanation:
Required
Which equals 

Collect like terms


Divide both sides by 2


Collect like terms


Divide both sides by 2


Collect like terms


Divide both sides by -2


Divide both sides by 2

Collect like terms



Divide both sides by 2

Collect like terms


Hence, the equations with the required solution are:



So if 2 people take 9 hours to paint the room and you want to know how long it will take if 3 people were painting first you will have to find the slope, or the rate of change, to do this you have to divide 9/2.
9/2= 4.5
So it take 4.5 hours for one person to paint the room.
Therefore if there where three people painting it would be 3 x 4.5= 13 hours and 30 minutes.
The time it would take to paint the room would increase.
Fraction that Sam painted in 1 min is:
10/25=2/5
Fraction that you painted in 1 min:
5/25=1/5
Fraction pained by both in 1 min:
1/5+2/5=3/5 ft²/min
Time taken to paint 50 ft² will be:
time=3/5×50=30 min
Thus we conclude that Sam was wrong.