kitty<3

Re:  what is 6.2% of 2,683.2

6.2% is the same as 0.062

So simply multiply 0.062 and 2683.2

You can do that on this site's calculator:

$${\mathtt{0.062}}{\mathtt{\,\times\,}}{\mathtt{2\,683.2}} = {\mathtt{166.358\: \!4}}$$

So you have: $${\frac{{\mathtt{x}}}{{\mathtt{9}}}}$$ = $${\frac{{\mathtt{1}}}{{\mathtt{81}}}}$$

Cross-multiply the equation.

x*81 = 9*1

Simplify.

81x = 9

Divide both sides by 81

x = 9/81

Simplify the fraction.

x = 1/9

Re:  quadratic formula

Which is

If you mean how to use it, it helps you find the zeros of a quadratic equation in the form $${{\mathtt{ax}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{bx}}{\mathtt{\,\small\textbf+\,}}{\mathtt{c}} = {\mathtt{0}}$$

This site can help you understand it:

http://www.purplemath.com/modules/quadform.htm

Slope: -2

Point: (3,1)

Slope-intercept form: y = mx+b

First use the point-slope formula: (y-y₁) = m(x-x₁) where (x₁,y₁) are the coordinates of the point and m = slope.

So:

y-1 = -2(x - 3)

Multiply out the -2.

y - 1 = -2x + 6

Add 1 to both sides.

y = -2x + 7

Well, the simplest way would be to divide them:

$${\frac{{{\mathtt{a}}}^{{\mathtt{8}}}}{{{\mathtt{a}}}^{{\mathtt{6}}}}}$$ would equal a^(8-6) which would equal a²

Another way would be to expand the expression:

$${\frac{\left({\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}\right)}{\left({\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}{\mathtt{\,\times\,}}{\mathtt{a}}\right)}}$$

And then simplify it to a*a

With two variables, you would need at least two equations to solve them.

However, you can expand 7(3a+6b), although that would not necessarily make it simpler:
Use the Distributive Property:

7*3a + 7*6b

= 21a + 42b

Just adding on to what Melody said earlier:)

Use the Law of Cosines if you have the three sides of a triangle and no angles.

For any triangle with 3 sides a, b, and c opposite angles A, B, and C:

This page explains different ways to use this law:

http://www.mathsisfun.com/algebra/trig-cosine-law.html

Hi Anonymous,

It would be easier to answer your question had you asked a specific example, but since you asked a general question, this is the general idea:

Assuming you mean special right triangles, they are 30-60-90 degree triangles and 45-45-90 degree triangles.

They are special because the ratio of their sides is always constant.

For the 30-60-90 triangle (on the right),

the side opposite the 30-degree angle is always x, a number.

The side opposite the 60-degree angle would always be square root 3 times that number x, and the side opposite the 90-degree angle (the hypotenuse) would always be 2 times that number x.

So if x= 3 for  30-60-90 triangle,

the side opposite the 60-degree angle would be $${\sqrt{{\mathtt{3}}}}{\mathtt{\,\times\,}}{\mathtt{3}}$$   < [3 sqrt(3),but the numbers come out white if I write it that way]  and the hypotenuse would be 6.

The 45-45-90 triangle works the same way.

If the side facing the 45-degree angle is 4, then the side facing the other 45-degree angle is also 4, and the side facing the 90-degree angle (the hypotenuse) would be $${\mathtt{4}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{2}}}}$$

So these triangles are useful in that once you memorize the ratios of the sides, you would be able to find the length of the sides without using trigonometry or the Pythagorean Theorem:)

In trigonometry, you use the basic sine, cosine, and tangent of angles in a triangle (the most basic is a right triangle)

The sine of an angle (A) would be the opposite side over the hypotenuse, the cosine of the angle would be the adjacent side over the hypotenuse, and the tangent of the angle would be the opposite side over the adjacent side.

Therefore, if you know the sine, cosine, or tangent of an angle, you can solve for the unknown side.

For example, if in the triangle below angle A is 60 degrees, and you know that the hypotenuse h is 2, you would use the sine of 60.

sin(60) = a /2 

a = 1.732050807568, or square root of 3

In cases that are not conveniently right triangles, you can use the Law of Sines and Law of Cosines to solve a triangle (find all its missing sides and angles)

Here is a page that can explain this better:

http://www.mathsisfun.com/algebra/trig-solving-triangles.html

On this site's calculator, just press "Enter" again after the answer appears, and the calculator will put it into scientific notation. http://web2.0calc.com/

You can also write an answer in scientific notation yourself by putting one digit before the decimal point, the rest behind the decimal point, and the number multiplied by 10 to the power of however many digits it takes to make the number.

Ex: 12345 = 1.2345 * 10⁴