Question 86810
In the morning, May drove to an appointment at 50 mph. Her average speed on the return trip in the afternoon was 40 mph. The return trip took 1/5 hour longer. How far did she travel to the appointment?
:
Let d = distance one way
:
Write a time equation:
Time = Dist/speed
:
Time out + (1/5) = time back
{{{d/50}}} + {{{1/5}}} = {{{d/40}}}
Mult equation by 200 to get rid of the denominators:
4d + 40 = 5d
40 = 5d - 4d
d = 40 mi
:
Check solution using the time:
40/50 = .8 hrs
40/40 = 1 hr which is .2 (1/5) hrs longer
:
:
Solve the problem.
Find the length of a rectangular lot with a perimeter of 72 m if the length is 8 m more than the width.
:
Let width = x
Then the length = (x+8)
:
2L + 2W = 72
Simplify:
L = W = 36
Substitute for L & W
(x+8) + x = 36
2x + 8 = 36
2x = 36-8
x = 28/2
x = 14 m is the width, the length: 14 + 8 = 22 m
:
Check solution
2(22) + 2(14) = 
44 + 28 = 72
:
:
Solve the problem.
A rectangular Persian carpet has a perimeter of 200 inches. The length of the carpet is 26 in. more than the width. What are the dimensions of the carpet?
Solve the problem.
:
Let width = x
Then the Length = (x+26)
:
Do this exactly the same way
:
:
A triangular shaped lake-front lot has a perimeter of 2200 ft. 
Let x = length of the shortest side:
:
One side is 200 ft longer than the shortest side,
One side = (x+200)
:
 while the third side is 500 ft longer than the shortest side.
Third side = (x+500)
: 
Find the lengths of all three sides.
x + (x+200) + (x+500) = 2200
;
You should be able to do this now.