Question 442824
4/x-4+28/x+4=4
4(x+4)+28(x-4)=4(x2-16)
4x+16+28x-112=4x2-64
0=4x2-32x+32
0=x2-8x+8
*[invoke quadratic "x", 1, -8, 8 ]
Throwing out the lower number, we get the speed of the boat in still water to be 6.828 mph..