Explain how you would estimate to subtract 189 from 643
1 answer:
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Answer:
StartFraction 50 miles Over 1 hour EndFraction = StartFraction 200 miles Over question mark hours EndFraction
Step-by-step explanation:
For constant speed, miles and hours are proportional. One possible equation is ...
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<em>Comment on the solution</em>
I personally like to put the unknown in the numerator, so the equation can be solved in one step. The equation above requires two steps: one to cross-multiply, and one to divide by 50.
I might write the equation as ...
(? hours)/(200 mi) = (1 hour)/(50 mi) . . . . multiply by 200 mi to solve
Another way to write the equation is matching the ratios of times to corresponding miles:
(? hours)/(1 hour) = (200 mi)/(50 mi)
This only requires simplification to solve it: ? = 4.