# Tutor profile: Willow B.

## Questions

### Subject: Basic Math

How do I know if a number is prime?

A prime number is a number greater than 1, and its factors must only be itself and 1 (factors are whole numbers that can be divided into another number). For example, 2 is a prime number because the only whole numbers that can be multiplied to get 2 are 1 and 2. 2 is the only even number that can be a prime number, because every other even number has 2 as a factor. A few other prime numbers are 3, 5, and 7 because their only factors are 1 and themselves.

### Subject: Calculus

How do you take the derivative of 5x^2 + 7x - 3?

In order to take a derivative, you multiply the power by the number in front of the x. Then, you reduce the power by 1. In this equation, for 5x^2 the power is 2. You multiply this by the 5 to get 10, and reduce the power from 2 to 1. You would get 10x^1, or simply 10x. For the next part, 7x, the power is 1 so it stays 7, then you reduce the power to 0. x^0 is 1, so it is just 7. For the last part, the power is already 0, so when it is multiplied by the 3 it all becomes 0. Your final answer ends up being 10x + 7.

### Subject: Algebra

How do I solve the equation 5x+7=23?

First, you want to get the numbers and variables on separate sides. In this equation, you would subtract 7 from each side, and then you get 5x=16. Then, to get x by itself you divide each side by 5. This gives you your answer, x=16/5.

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