Can someone please solve these 4 matrix problems for me please!

[marlinsmaniac20]

1)
4x - 7y = -2
-x + 2y = 1 (solve into rref) by hand!

2) x + y + z = 4
x + 3y +2z = 4
x-2y+z=7 (rref too)

3) if A= [1.2] (all one set) Then A^ -1 =?
[2.3]
4) if B = [ 6.-1.-5
-7. 1. 5
-10.2.11
than B^ - 1 = ?

 

[tkhunny]

Are you sitting in the exam right now?

Please show your work. You MUST have SOME clue or you are in the wrong class. This late in the year, that could be quite a problem.