SOLUTION: please help I don't know how to set up an equation to solve this problem Mackenzie can bicycle 69 miles in the same time as it takes her to walk 27 miles. She can ride 7 mph fas

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Question 768700: please help I don't know how to set up an equation to solve this problem
Mackenzie can bicycle 69 miles in the same time as it takes her to walk 27 miles. She can ride 7 mph faster than she can walk. How fast can she walk?
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Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
Mackenzie can bicycle 69miles in the same time as it takes her to walk 27miles.
69mil%2Fs=t...............s= speed when she bicycle
27mil%2Fs%5B1%5D=t..............s%5B1%5D= speed when she
since time is same, =>
69miles%2Fs=27mil%2Fs%5B1%5D

since she can ride 7mph faster than she can walk, then speed
s=s%5B1%5D%2B7mph.......plug it in equation above

69mil%2F%28s%5B1%5D%2B7mil%2Fh%29=27mil%2Fs%5B1%5D....solve for s%5B1%5D

69mil%2As%5B1%5D=27mil%28s%5B1%5D%2B7mil%2Fh%29

69mil%2As%5B1%5D=27mil%2As%5B1%5D%2B189%28mil%5E2%2Fh%29..cancel mil

69%2As%5B1%5D-27%2As%5B1%5D=189%28mil%2Fh%29

42s%5B1%5D=189%28mil%2Fh%29

s%5B1%5D=%28189%2F42%29%28mil%2Fh%29

s%5B1%5D=4.5%28mil%2Fh%29.......she walks with a speed of 4.5%28mil%2Fh%29

s=s%5B1%5D%2B7mph=>s=4.5%28mil%2Fh%29%2B7mil%2Fh=> s=11.5%28mil%2Fh%29

let’s check is time same for given distances above:

69mil%2Fs=t=>69mil%2F11.5%28mil%2Fh%29=t=>6h=t
27mil%2Fs%5B1%5D=t=> 27mil%2F4.5%28mil%2Fh%29=t=>6h=t