Please, help me. I don’t think this problem makes sense.

m<BCD = 130 degrees

9x - 5 = 4x + 5 + 65

simplify

9x - 5 = 4x + 70

add 5 to both sides

9x = 4x + 75

subtract 4x from both sides

5x = 75

divide both sides by 5

x = 15

substitute 15 for x

9(15) - 5

135 - 5

130

Therefore, m<BCD = 130 degrees

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