4. Use matrices to solve the following three simultaneous equations. Set up the equations in the format [A][X]=[B] and solve the equations using [X]=[A][B]. Use your matmult function to do the multiplication. You may use the built-in MATLAB function for taking the inverse of a matrix. 3a + 4b = 23 4a + 10b = 12 x + 2y + 4z = 11 4x - 2y + z = 8 2x +5y +2z = 3 X1 + x2 + 3x4 = 4 2x1+ X2 X3 + X4 = 1 3x1 - x2-X3 +2x4 = -3 -X1 +2x2 + 3x3 - X4 = 4