- 2 + 10x³ - 21x² + 19x - 4
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
go on the tube you might find some information there
a variable is any characteristics, number, or quantity that can be measured or counted. a variable may also be called a data item. hope i !