# Thread: Help with a few problems

1. ## Help with a few problems

1) Help please! Can someone find the slope of the line above ^^^ with the coordinates (-2, -3) and (3, 7).
2) Now for the hexagon problem:: A regular hexagon has rotational symmetry about its center. What is the minimum number of degrees of rotation necessary to show rotational symmetry? Explain your reasoning using math vocabulary.
3) Write in a simpler, shorter form without parentheses! SIMPLIFY!:

-2(3x-5)+2x-2(5-x)

Thank you!

2. Originally Posted by peachgal

1) Help please! Can someone find the slope of the line above ^^^ with the coordinates (-2, -3) and (3, 7).
2) Now for the hexagon problem:: A regular hexagon has rotational symmetry about its center. What is the minimum number of degrees of rotation necessary to show rotational symmetry? Explain your reasoning using math vocabulary.
3) Write in a simpler, shorter form without parentheses! SIMPLIFY!:

-2(3x-5)+2x-2(5-x)

Thank you!
1) The slope between two points $(x_1, y_1) \text{ and }(x_2, y_2)$ is $m = \frac{y_2 - y_1}{x_2 - x_1}$.

2) There are 6 points on the hexagon. If you inscribed a circle about the hexagon, what is the central angle between two of the points?

3) Is this
$-2(3x - 5) + 2x - 2(5 - x)$
or
$-2(3x - 5) + (2x - 2)(5 - x)$

-Dan

3. Originally Posted by topsquark
1) The slope between two points $(x_1, y_1) \text{ and }(x_2, y_2)$ is $m = \frac{y_2 - y_1}{x_2 - x_1}$.

2) There are 6 points on the hexagon. If you inscribed a circle about the hexagon, what is the central angle between two of the points?

3) Is this
$-2(3x - 5) + 2x - 2(5 - x)$
or
$-2(3x - 5) + (2x - 2)(5 - x)$

-Dan
I'm sorry I wish I could be smart but I am absolutely horrible with angles.

4. Originally Posted by peachgal
I'm sorry I wish I could be smart but I am absolutely horrible with angles.
A circle has how many degrees?

-Dan

5. Originally Posted by topsquark
A circle has how many degrees?

-Dan
360
By the way on #2 it said simplify WITHOUT using parentheses. Can you please do that?

6. Originally Posted by peachgal
360
And you have six points on the hexagon. So how far do you have to rotate the hexagon before it looks like the original hexagon again? (In other words, rotate the hexagon, but leave a copy of it in it's original position. How far do you have to rotate the hexagon before it covers the copy?)

-Dan

7. Originally Posted by peachgal
3) Write in a simpler, shorter form without parentheses! SIMPLIFY!:

-2(3x-5)+2x-2(5-x)

Thank you!
You know that $a(b + c) = ab + ac$. So the first term, for example gives:
$-2(3x - 5) = (-2)(3x) + (-2)(-5) = -6x + 10$

You do the third term.

-Dan

8. Originally Posted by topsquark
And you have six points on the hexagon. So how far do you have to rotate the hexagon before it looks like the original hexagon again? (In other words, rotate the hexagon, but leave a copy of it in it's original position. How far do you have to rotate the hexagon before it covers the copy?)

-Dan
60 degrees ok now i get it