Question

以知:√(X-100)+√(100-X)+21=Y,求X+Y所得结果的平方根

Answer 1

根号(X-100)+根号(100-X)+21=Y,

x-100≥0,100-x≥0,所以x=100

所以0+0+21=Y

Y=21

±根号(X+Y)=±根号（100+21）=±11