x^2+(48/x)^2=100
两边同乘以x^2得：x^4+48^2=100x^2
即：x^4-100x^2+48^2=0
设y=x^2,则上式变为y^2-100y+48^2=0
解一元二次方程得：y1=64,y2=36
y=x^2所以,x1=8,x2=-8,x3=6,x4=-6