Your friend incorrectly factors the expression 15x — 20xy as 5x(3— 4xy

no 15x — 20xy as 5x(3— 4xy is not correct

Step-by-step explanation:

15x — 20xy ≠ 5x(3— 4xy)

there are not equal because 5x(3 - 4xy) =

when you simplify the bracket, you will have

15x - 20x²y

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

may i see the picture? it would a lot, xox