pivot the system about the element in row 2, column 1. (enter the augmented matrix with all cells in their original position.)
1 2 4 3
2 8 6 4
−1 4 2 3

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b

b. 153 students do not participate in sports and seventy-five 12th graders were surveyed