explain please too! i really am struggling with this and I don't know how the results are achieved. thanks!

Angle 1 = 180°-99° (adj angles on a str line)

= 81°

Angle 2 = 99° (vert opp angles)

Angle 3 = 81° (vert opp angles)

Angle 4 = 99° (corr angles, a//b)

Angle 5 = 81° (corr angles, a//b)

Angle 6 = 99° (corr angles, a//b)

Angle 7 = 81° (corr angles, a//b)

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

thats not a system of equations, that is a solution