Determine the constant that should be added to the binomial so that it becomes a perfect square trinomial. Then write
and factor the trinomial.
-$$x ^ { 2 } - 18 x$$
A) $81 ; x ^ { 2 } - 18 x + 81 = ( x - 9 ) ^ { 2 }$
B) $- 324 ; x ^ { 2 } - 18 x - 324 = ( x - 18 ) ^ { 2 }$
C) $324 ; x ^ { 2 } - 18 x + 324 = ( x - 18 ) ^ { 2 }$
D) $- 81 ; x ^ { 2 } - 18 x - 81 = ( x - 9 ) ^ { 2 }$

Question

Quizplus · Accepted Answer

To form a perfect square trinomial from $x^2 - 18x$, add $(\frac{-18}{2})^2 = 81$. Factoring the resulting trinomial gives $(x - 9)^2$.

Determine the Constant That Should Be Added to the Binomial x2−18xx ^ { 2 } - 18 xx2−18x

Determine the Constant That Should Be Added to the Binomial $x ^ { 2 } - 18 x$