# Tutor profile: Chevonese A.

## Questions

### Subject: Chemistry

What is an isotope?

An isotope is two or more forms of the same element with the same atomic number but different mass number, meaning the same number of protons but different number of neutrons.

### Subject: Biology

What are some of the differences between an animal and plant cell?

Plant cells have a cell wall while animal cells do not. Plant cells have chloroplasts while animal cells do not. Plant cells have vacuoles while animal cells do not.

### Subject: Algebra

Solve the equation by completing the square: x^2 + 6x - 7 = 0

1. All variables should be on side and numbers on the other side of the equal sign. Move -7 to the other side of the equal sign to give you: x^2 + 6x = 7 (When variables or numbers are moved from one side of an equal side to the other, the sign changes to the opposite.) 2. Take half of the coefficient of the x term (or divide it by 2, the same thing) and then square it. So one-half of 6 is 3. 3 squared will give you 9. 3. Add 9 to both sides of the equation to give you: x^2 + 6x + 9 = 7 + 9 4. Factor the left side of the equation and simplify the right. This will give you (x+3)(x+3) = 16 5. (x+3)(x+3) = 16 can be simplified to (x+3)^2 = 16 6. Find the square root of both sides of the equation. This will give you x+3 = ±4 7. Solve for x by breaking the plus or minus sign into separate equations. This will give you x+3=-4 and x+3=4. x+3= -4 Subtract 3 from both sides to get x by itself x+3-3 = -4 -3 x = -7 x+3 = 4 Subtract 3 from both sides to get x by itself x+3-3 = 4-3 x = 1 x= -7, 1

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