We can see that there is a negative square root of 5 and a positive square root of 5. They cancel out. In addition, we know that two-halves are equal to 1.
Since the square root of 5 can be thought of as 5 to the one-half power, we should evaluate that first.
Substitute 2.236 for the square root of 5.
Multiply. 1.118 + 1
Add. 2.118
So the expression is approximately equal to 2.118 (exactly 2.1180339887498948482045868343656).