If X is a square matrix such that X^2 = -I then X is invertible. True or False?

Aflute is on sale for 20% off. including the discount and 8% tax, the sales price is $216.

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?

What is the ordered pair of m’ after point m (5, 6) is rotated 90° counterclockwise?