Solve XA = B

Problem

Solve the matrix equation X*A = B for the 2x2 matrix X, where A is invertible.

Return X = B * inv(A) as a matrix of floats, or None if det(A) == 0.

Hint

Multiply on the right by the inverse of A, not the left.

case 1

in: [[[1,0],[0,1]],[[1,2],[3,4]]]

expected: [[1,2],[3,4]]

case 2

in: [[[2,0],[0,3]],[[2,6],[6,12]]]

expected: [[1,2],[3,4]]

case 3

in: [[[1,2],[3,4]],[[1,0],[0,1]]]

expected: [[-2,1],[1.5,-0.5]]

case 4

in: [[[1,2],[2,4]],[[1,1],[1,1]]]

expected: null

Starter codePython

def solve_xa(A, B):
    # Your code here
    pass

4 test cases · run your code against them in the editor