What statement makes the open sentence true ? 49 - 7x = 21 a. x= 11 b. x=7 c. x=4 d. x=3

The answer is C. x=4

Explanation) 49 - 7 (4) = 21

7 (4) = 28

49 - 28 = 21

7

step-by-step explanation:

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