Which of the following is a biconditional statement?
A) A shape has four sides if and only if it's a quadrilateral.
B) If a shape is a quadrilateral, then it has four sides.
C) If a shape doesn't have four sides, then it isn't a quadrilateral.
D) if a shape has four sides, then it's a quadrilateral.

The ivring berlin learning center would like a possible net profit of $650,000 on its new resource manual it sells to schools. the fixed costs for producing the manual are $780,000 and the variable cost per package is $19.85. if the estimated unit sales are 1,250,000 units, what selling price unit should the ivring berlin learning center try?