A20% acid solution is mixed with a 70% acid solution to get 50 liters of a 40% solution.
which of the following expressions is equal to 4(50)

a. 0.2x+ 0.7y
b. 2x + 7y
c. x+y

B. 2x + 7y  100%  sure just got it right

Step-by-step explanation:

B. 2x + 7y

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