A, B and C are matrices such that: A=(2 1), B = and C=(5 6). Given
that AB=C, calculate the values of x and y ?

i) Using a matrix method, solve the pair of simultaneous equations
2x-y=0
x+3y=7​

Suppose you are choosing a 6-digit personal access code. this code is made up of 4 digits chosen from 1 to 9, followed by 2 letters chosen from a to z. any of these digits or letters can be repeated. find the total number of personal access codes that can be formed. 492,804 341,172 39,917,124 4,435,236