Can someone hep explain this plese

How do i simply this radical expression?

Summary statistics given for independent simple random samples from two populations. use the pooled t-interval procedure to obtain specified confidence interval. x1=71.6, s1=3.9, n1=11, x2=67.9, s2=3.4, n2=9 determine a 99% confidence level.

Which inequality represents all the values of x for which the quotient below is defined? √x+1 ÷ √ 4-x