Dina encoded a secret phrase using matrix multiplication. She multiplied the clear text code for each letter by the matrix (See
image) to get a matrix that represents the encoded text. By which matrix does Dina multiply the encoded text to get the matrix for the clear text code?
Dina needs to multiply by the inverse of C. The inverse of a 2×2 matrix is easily calculated from its definition: the transpose of the cofactor matrix divided by the determinant. Here, that is
I will assume that this question is about scientific notation (also assuming that the first number is 3.4*10^2), where you can arrange the numbers by the exponent of the 10, so from least to greatest: , , 435, and