waecmaths question:
The mean of the number 2, 5, 2x and 7 is less or equal to 5. Find the range of values of x
Option A:
$x\le 3$
Option B:
$x\ge 3$
Option C:
$x<3$
Option D:
$x>3$
waecmaths solution:
$\begin{align} & \frac{2+5+2x+7}{4}\le 5 \\ & \frac{14+2x}{4}\le 5 \\ & 14+2x\le 20 \\ & 2x\le 6 \\ & x\le 3 \\\end{align}$
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