Answer:
C Substitution
Step-by-step explanation:
In statement 5, we are substituting statements 3 and 4 into statement 2
A= 35° because 180°-80°-65°= 35°
b=50° because 180°-95°-35°= 50°
c=85° because 180°-95°= 85°
d=30° because 180°-65°-85°= 30°
For these you just have to remember that the sum of the angles of a triangle is 180°, and the same for a straight line.
Let (15+x) and (22+x) be the future ages of the brothers
15+x+22+x= 408
Collect like terms
37+2x=408
Move 37 to the other side as a negative number
2x=371
Divide both sides by 2
371/2 is 185.5
So, after 185.5 years, their ages will add up to be 408