She swims for 2.5 hours at a rate of 2 km/hr
Multiply 2.5 * 2 = 5 km
Negative five pi divided by two
It looks equivalent.
Do the Pythagorean theorem on the triangle shown.
2.1^2-1.4^2
4.2-1.96=2.24
Sqrt of 2.24 is 1.496 or 1.5
Now multiply this by 2 to get the length of x
HOPE THIS HELPS

Parallel lines share the same slope, so the slope of the parallel line in this case must be
.
Point-slope form is
, where
is the slope and
is any known point on the line.
Plug in the values. 
Simplify and distribute. 
Subtract 1 from both sides. 