What completes this expression to make it a eerfect square trinomial? \( x^{2}+4 x+ \) A 2

To complete the expression \( x^{2}+4x+ \) into a perfect square trinomial, you need to add the square of half the coefficient of \( x \). In this case, half of 4 is 2, and squaring it gives you \( 2^2 = 4 \). So, adding 4 completes the expression as \( x^{2}+4x+4 = (x+2)^2 \). Perfect square trinomials are like magic spells in algebra! When you spot a perfect square trinomial, it can help you quickly factorize expressions or solve equations. They usually take the form of \( (a + b)^2 = a^2 + 2ab + b^2 \). Recognizing this pattern can save you tons of time on homework and tests!