On a math test a student, Sarah, has to identify all the coefficients and constants of the expression 9 b + 4 + y. Sarah says that 9 is a coefficient and 4 is a constant. Identify all the coefficients and constants of the expression. What error might Sarah have made?

Step-by-step explanation:

4 + n + 7m

constants are just the numbers with no variables (letters)

so the constant is 4

coefficients are numbers multiplied by variables (letters)

so the coefficients are : 7 and 1

the error sarah made is forgetting the coefficient of nbecause even if it is not written, n is the same as 1nso basically, there is a coefficient for EVERY variable, even if its not written.

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