Bài 1. Tìm ma trận nghịch đảo của các ma trận sau A=


−1 −1 2
3 2 −5
−2 −1 −1

 ; B=


1 −1 0 0
−1 1 −1 0
0 −1 1 −1
0 0 −1 1


; C=


1 −1 −1 −1
−1 1 −1 −1
−1 −1 1 −1
−1 −1 −1 1



Astudent received the following grades last semester. find the student's semester grade point average. an a is algebra (3 credits), a b in history ( 3 credits), a in sociology ( 3 credits) a d in english ( 3credits) and a c in seminar ( 2credits). an a is worth 4 points, a b is worth 3 points a c is worth 2 points and a d is worth 1 point.

Brook states that the distance on the line is 4 units. caleb states that the whole line does not have a distance because it continues on forever. vivian states that the line is 6 units long. which distance did brook measure? which distance did vivian measure?

Select the sequences that are geometric.