x^2-10x+22≤0
得x^2-10x+22=0
Δ=b^2-4ac=100-4x1x22=22
x=﹙-b±ΓΔ﹚／2a=﹙10±Γ22﹚／2
x1=﹙10+Γ22﹚／2
x2=﹙10-Γ22﹚／2