How do I prove that the figure is a rectangle ?
I really need help I don’t know what to do.

Hey, sorry I couldn't help you more on this but, to me it doesn't really look like a rectangle, but it could be the pov of the camera. In order for something to be a rectangle it has to follow these four rules:

- The opposite sides are parallel and congruent

- The diagonals bisect each other

- There are four right angles

- The diagonals are congruent

- 2 + 10x³ - 21x² + 19x - 4

step-by-step explanation:

each term in the second factor is multiplied by each term in the first factor

x²(- 2x² + 4x - 1) - 3x(- 2x² + 4x - 1) + 4(- 2x² + 4x - 1) ← distribute

= - 2 + 4x³ - x² + 6x³ - 12x² + 3x -8x² + 16x - 4

collect like terms

= - 2 + 10x³ - 21x² + 19x - 4 ← in standard form