21x^2-2x-3. factor by grouping (ac method)

Rewrite -2x into 7x-9x
21x^2+7x-9x-3
group the first two terms, then group the last two terms: (21x^2+7x)-(9x+3)
7x(3x+1)-3(3x+1)
so (3x+1)(7x-3)

Answercounterclockwise rotation about the origin by 180 degrees followed by reflection about the y-axisexplanationthe given figure has verticesrecall that for counterclockwise rotation about the origin, when we rotate figure pqrs counterclockwise through an angle of 180° about the origin, the coordinates will becomenext, we reflect in the y-axis by negating the x-coordinates of the resulting figure to obtain,therefore the correct answer is c