QuestionTotal: X marks
1. What value of $k$ makes the expression a perfect square trinomial? Write each expression as the square of a binomial. (1 mark each, for a total of 2 marks) a) $x^{2}+9 x+k$ b) $x^{2}-7 x+k$

Studdy Solution
For the expression $x^2 + 9x + k$, the value of $k$ that makes it a perfect square trinomial is $k = \frac{81}{4}$.
The expression can be written as $\left(x + \frac{9}{2}\right)^2$.
For the expression $x^2 - 7x + k$, the value of $k$ that makes it a perfect square trinomial is $k = \frac{49}{4}$.
The expression can be written as $\left(x - \frac{7}{2}\right)^2$.