3x-10=x+4 is the equation...
$1.40 - price from a supplier = 100%
100% + 80% = 180% = 1,8 - the retail price
1,40 * 1,8 = $2,52 - the retail price
100% - 25% = 75% = 0,75 - on sale for 25% off
2,52 * 0,75 = $1,89 - the sale price.
See the picture attached to better understand the problem
we know that
A quadrilateral is called Cyclic quadrilateral <span>if its all vertices lie on the circle.
</span><span>The opposite angles of a Cyclic - quadrilateral are supplementary
</span>so
∠A+∠C=180°
and
∠
B
+∠D=180°
therefore
the answer is<span>
C) The sum measure of ∠B and ∠D equals 180°</span>