Answer:
Step-by-step explanation:
Simultaenous Equations
a + 2d = 8
a + 7d = 33
By subtracting one equation from the other
(a + 7d = 33) - (a + 2d = 8)
(a - a) + (7d - 2d) = (33 - 8)
5d = 25
d = 25/5
d = 5
Now replace d in either equation to solve for a
a + 2(5) = 8
a + 10 = 8
a = 8 - 10 = -2
a = -2
a + 7(5) = 33
a + 35 = 33
a = 33 - 35 = -2
a = -2
Response:
Her brother catches up to her at 11 am + 4 hours = 15 p.m
Detailed explanation:
Provided information;
Ariel's speed = 45 mph
She departed at 9 a.m
Her brother's speed = 60 mph
He began at 11 a.m
Inferred from the question: Since Ariel's speed is 45 mph, after two hours she is ahead by 90 miles.
Meanwhile, her brother travels at 60 mph, hence he is traveling (60 - 45) = 15 mph faster
Therefore, with this speed, he will catch up to her in = 4 hours.
So her brother catches up with her at 11 am + 4 hours = 15 p.m