2. the number of people at the sale was 210 to start off with. when you arrived if 50% of the people left. how many people were left?

Well, we know that 50% of people left. Since there can be no greater than 100%, we know that stayed.

Now, we need to figure out what 50% of 210 is. To do this, we can convert 50% into a fraction:

Now, let's multiply this fraction by 210 to find a number of people. This would be:

Our answer is 105 people.

- 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