Question

Does anyone know how to do this? This looks familiar to me but I don’t know what to do.

Answer 1

Let us set x for the missing score.

Now, if he wants to keep an average of 86 or greater, we need to use the next inequality:

$\frac{68+84+x}{3}≥86$

Then, we need to solve for x:

$\frac{152+x}{3}≥86$

Multiply both sides by 3:

$\begin{gathered} (3)\frac{152+x}{3}≥(3)(86) \\ 152+x≥258 \end{gathered}$

Subtract both sides by 152:

$152-152+x≥258-152$

Simplify:

$x≥104$

In this case, the score is 104 is greater than the possible number of points.

Hence, enter DNE