Question 141076
How do I solve using a system of two equations in two variables? 
When Lucy swims with the current, she swims 18km in 2 hours. Against the current, she can swim only 14km in the same time. How fast can Lucy swim in still water? What is the rate of the current?
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Let her still water speed be "s"; Let current speed be "c".
EQUATIONS:
s + c = 18 km/2 hrs
s - c = 14 km/2 hrs
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I think you can solve for s and c.
Cheers,
Stan H.