Find the matrix A such that
Given,
As A is multiplied with a matrix of order 3×2 and gives a resultant matrix of order 3×3
For matrix multiplication to be possible A must have 2 rows and as resultant matrix is of 3rd order A must have 3 columns
∴ A is matrix of order 2×3
Let A = where a, b, c, d, e and f are unknown variables.
∴
∴ By matrix multiplication we have-
By equating the elements of 2 equal matrices we get-
a = 1 ; b = -2 and c = -5
also,
2a – d = -1 ⇒ d = 2a + 1 = 2 + 1 = 3
∴ d = 3
2b – e = -8 ⇒ e = 2b + 8 = -4 + 8 = 4
∴ e = 4
Similarly, f = 2c + 10 = 0
∴ A =