# Tutor profile: Olivia M.

## Questions

### Subject: Chemistry

How do you know if an ion is positively or negatively charged?

The charge of an atom is determined by whether it's a metal or a nonmetal. Metals will be primarily located on the left-hand side and center of the periodic table, and nonmetals will be primarily on the right-hand side of the table. It would be a good idea to memorize precisely where the elements switch from metals to nonmetals on the periodic table. Metals will always be cations and will have a positive charge. Nonmetals will always be anions and will have a negative charge.

### Subject: Calculus

Find the limit as x approaches 3 for (5x^2 - 8x - 13) / (x^2 - 5)

To solve this problem, substitute 3 in for every x value, then solve. The first line of work should read: [5(9) - 8(3) - 13] / [9 - 5] [42 - 24] / 4 18 / 4

### Subject: Algebra

Evaluate 30 - 12 ÷ 3 × 2 =

This question is asking for you to utilize the order of operations (PEMDAS): P - parenthesis E - exponents M - multiplication D - division A - addition S - subtraction Since there aren't any parenthesis, start with multiplication and division. Since the division sign appears before the multiplication sign in this problem, solve 12 ÷ 3 first. Your next line of work should read 30 - 4 x 2. The next step is to solve the multiplication portion of this problem. 4 x 2 = 8, so the next line should be: 30 - 8. Finally, finish the problem by subtracting. Your final answer should be 22.

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