Answer:
[tex]n^2 + \frac{5}{2}n + \frac{25}{16}[/tex]
[tex](n + \frac{5}{4})^2[/tex]
Step-by-step explanation:
Given
[tex]n^2 + \frac{5}{2}n[/tex]
Required
(a) Make a perfect square trinomial
(b) Write as binomial square
Solving (a)
Let the missing part of the expression be k;
This gives
[tex]n^2 + \frac{5}{2}n + k[/tex]
To solve for k, we need to square half the coefficient of n;
i.e. Since the coefficient of n is [tex]\frac{5}{2}[/tex], then
[tex]k = (\frac{1}{2} * \frac{5}{2})^2[/tex]
[tex]k = (\frac{5}{4})^2[/tex]
[tex]k = \frac{25}{16}[/tex]
Hence;
[tex]n^2 + \frac{5}{2}n + k[/tex] = [tex]n^2 + \frac{5}{2}n + \frac{25}{16}[/tex]
Solving (b)
[tex]n^2 + \frac{5}{2}n + \frac{25}{16}[/tex]
Expand [tex]\frac{5}{2}n[/tex]
[tex]n^2 + \frac{5}{4}n+ \frac{5}{4}n + \frac{25}{16}[/tex]
Factorize
[tex]n(n + \frac{5}{4})+ \frac{5}{4}(n + \frac{5}{4})[/tex]
[tex](n + \frac{5}{4})(n + \frac{5}{4})[/tex]
[tex](n + \frac{5}{4})^2[/tex]
Hence:
[tex]n^2 + \frac{5}{2}n + \frac{25}{16}[/tex] = [tex](n + \frac{5}{4})^2[/tex]
