(2x - 3)(5x² - 2x + 7)
= 2x(5x² - 2x + 7) -3(5x² - 2x + 7) multiplied using distributive property
= 10x³ - 4x² + 14x -15x² + 6x - 21 distributed 2x and -3
= 10x³ - 19x² + 20x - 21 added like terms
You did not upload the image of the steps so I am not sure where fiona made the error. Hopefully, you can figure it out from the information I provided.