# Problem of the Day

Consider the set . If the arithmetic mean of this set is 3, which of the following could be the value of ?

A.

B.

C.

D.

E.

### Solution

[latexpage]

${x^2+x,9,10x,x^2-16x}$ Â has 4 terms. If the arithmetic mean of this set is 3, then the sum of the terms must be 12. This gives us the following equation:

$x^2+x+9+10x+x^2-16x=12$

$2x^2-5x-3=0$

$(2x+1)(x-3)=0$

$x=3,-\frac{1}{2}$

Comments are closed.