x+根号下x-1=3和根号下x+10-6/根号下x+10=5

Question

x+根号下x-1=3和根号下x+10-6/根号下x+10=5

Answer 1

x+√(x-1)=3 设t=√(x-1),x=t+1,带回去 t+1+t=3,(t+2)(t-1)=0,t=1.t=-2(舍）,x=0 设x+10=t(t>0),t-6/t=5 t-5t-6=0,(t-6)(t+1)=0,t=6,x=-4