如图,在△ABC中,角C=90度,P为斜边AB上的一点,且P与A不重合,过P作PE垂直于AB交AC于E(E与C不重合),

AC=√(AB^2-BC^2)=6
△ABC~△AEP
PE/AP=BC/AC,PE=AP*BC/AC=x*8/6=4x/3
AE/AP=AB/AC,AE=AP*AB/AC=x*10/6=5x/3
BP=AB-AP=10-x
CE=AC-AE=6-5x/3
y1=BP+PE+CE+BC
=10-x+4x/3+(6-5x/3)+8
=24-4x/3
y2=BP*PE/2+BC*CE/2
=(10-x)*4x/3*1/2+(6-5x/3)*8*1/2
=2x(10-x)/3+4(6-5x/3)
=24-2x^2/3