On the first down, the chargers had the ball on their 25 yard line. on the next three downs they lost six yards gained 10 yards and lost 8 yards what was the yard line at the end of the 4th down

lost means subtract and gained means add

25 lost 6 gained 10 lost 8

25 - 6 + 10 - 8

19 + 10 - 8

29 - 8

21

21 yard line

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