Simplify the trinomial square \((x + 5)^2\).

Step 1 ：\((x + 5)^2 = (x + 5) * (x + 5)\)

Step 2 ：\((x + 5) * (x + 5) = x^2 + 5x + 5x + 25\)

Step 3 ：\(x^2 + 5x + 5x + 25 = x^2 + 10x + 25\)