James called an electrician to fix a problem in his house. The electrician charges $30 to come out to the house & $25 an hour while fixing the leak. If the final bill was $105, write an equation & solve to find how many hours the plumber was at David's house.

hi,

3. 12.15, you are correct.

4.2.01, your first digit is correct,

hope this !

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

addition

step-by-step explanation: