A - area of a trapezoid;
a, b - two bases.
A = h * ( a + b ) / 2 / * 2 ( we have to multiply both sides by 2 )
2 A = h *( a + b )
2 A = h a + h b
h b = 2 A - h a
b = ( 2 A - h a ) / h
b = 2 A/h - a
Answer: D )
The average rate, in miles per hour, of the rail portion of the trip is; D: 75
<h3>How to calculate the average speed?</h3>
Since exactly 1/3 of the distance travelled was by rail, then we can say that;
(1/3) * (90) = 30 miles
We are told that part of the trip took 1/5 of the travel time. Thus;
Time it takes to travel that distance is:
(1/5) * (2) = 2/5 of an hour
Average rate is;
30/(2/5) = 150/2 = 75 mph
Read more about Average speed at; brainly.com/question/4931057
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Answer:
8 N + 2
Step-by-step explanation:
==> 8 N + 2
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