Answer:
Step-by-step explanation:
Expression evaluated by the student is,
(-4 + x)
For x = [tex]-9\frac{1}{2}[/tex]
Value of the expression will be,
(-4 + x) = [tex]-4+(-9\frac{1}{2})[/tex]
= [tex]-4-9-\frac{1}{2}[/tex]
= [tex]-13-\frac{1}{2}[/tex]
= [tex]-13\frac{1}{2}[/tex]
While student evaluated the value of the expression as [tex]-5\frac{1}{2}[/tex].
Mistake done by the student may be in the first step [tex][-4+(-9\frac{1}{2})][/tex].
He might have subtracted [tex](-9\frac{1}{2})[/tex] from (-4).