One of the five given matrices represents an orthogonal
projectiononto a line and another represents a reflection about a
line. identify both and briefly just choice.

Please see attachment

Step-by-step explanation:

Please see attachment

7! = 7×6×5×4×3×2

3! = 3× 2

as 7! is multiple of 3! because 7! contains 3! that is 3× 2 as factor

so 7! /(3! ) = 7× 6× 5× 4

= 42 × 20

= 840

its b) 840✌✌✌

dhruv⭐