# Tutor profile: Rachel W.

## Questions

### Subject: Geometry

If a circle has the diameter of 8, what is the circumference?

The answer is 25.13 To find this, we use the equation: C=2πr For consistency sake, always use 3.141 for π. The radius of a circle is half its diameter; in this case, since the diameter is 8, the radius will be 4. We then plug those numbers into the equation. so that the equation now looks like a simple multiplication problem: C= 2 x 3.14 x 4

### Subject: Pre-Algebra

A rectangle is 9 meters long and 4 meters wide. What is its area?

The area is 36 meters squared. To find this, we use the formula: A=lw (Area=length X width). We multiply the two numbers, nine and four, and find that our answer is 36 meters squared.

### Subject: Algebra

5(-3x - 2) - (x - 3) = -4(4x + 5) + 13

The answer is 0=0 First, we need to start with the Distributive Property, wherein we multiply the 5 by the first set of parenthesis. EX: 5 times -3x and 5 times -2.Next, multiply the '-' by the next set of parenthesis. EX: - times x and - times -3. Now, you want to handle the other side of the equation, do the same with the -4 and the parenthesis (4x +5) Your equation should now read: -15x -10 -x +3=16x-20+13 Now, combine like terms on each side: -16x-7=-16x-7 Now, combine like terms on both sides. This means, we need to move all the 'x' numbers to one side, and all the regular numbers to the other side. For this equation, let's add 16x to both sides, so that is cancels out on the left, and when added to the right side, equals zero. Now add the -7 from the right side to the left side, so that it cancels out on the right, and when added to the left, equals zero. Therefore, your equation is now: 0=0x, but since you cannot have a "0x", your answer is: 0=0

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