Its simple, really. in these cases, just plug your limits into the equation. So, for 38, you would have the square root of 5+4(which is the square root of 9, which turns into 3) -2 divided by 5. 3-2=1, so your limit would equal 1/5.
As for 46, its a little bit difficult. if you substitute 1 into the equation, you would end up with 0/0, which is something you cant have. so you have to get rid of the denominator, which means factoring the top. The top factors into (t+2)(t-1). the denomiator is reduced into (t-1)(t+1). Now, the two (t-1)s cancel out, leaving you with t+2 over t+1. Now, here is when you substitute t for 1. 1+2 over 1+1 = 3/2.