The answer is going to be 20x-4
See the attached figure to better understand the problem
we know that
AM=MD
so
triangle AMD is an isosceles right triangle
therefore
its height is half its width.
Then
AB = (1/2)AD----------Equation 1
Perimeter=2*[AB+AD]=34 in ---------> AB+AD=17-------> Equation 2
I substitute 1 in 2
(1/2)AD +AD = 17
(3/2)AD=17
AD=17*2/3----------> AD=34/3-------> 11 1/3 in
AB=(1/2)AD--------> AB=(1/2)*34/3--------> AB=17/3-------> AB=5 2/3 in
the answers are
AD=11 1/3 inAB = 5 2/3 in
4 hours = 304 miles.
1 hour = 304 ÷ 4
1 hour = 76 miles
7 1/2 hours = 76 x 7 1/2
7 1/2 hours = 570 miles.
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Answer: It will travel 570 miles in 7 1/2 hours.
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If 1 recipe = 4 1/4 = 4.25 cups
Then 1/2 = 0.5 recipe = 0.5 x4.25
=2.125
=17/8 cups