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it costs 13.79 on khan

it costs 13.79 on khan

SAVE ME!

The formula for finding the area of a triangle is base X height divided by 2. The formula for finding the area of a rectangle or square is just base X height. 

Simplify the following:
-5 a^2-4 a (2 a+3 b)

Factor a out of -5 a^2-4 a (2 a+3 b), resulting in a (-5 a^(2-1)-4 (2 a+3 b)):
a (-5 a^(2-1)-4 (2 a+3 b))

2-1 = 1:
a (-5 a-4 (2 a+3 b))

-4 (2 a+3 b) = -8 a-12 b:
a (-8 a-12 b-5 a)

Grouping like terms, -5 a-8 a-12 b = -12 b+(-5 a-8 a):
a (-12 b+(-5 a-8 a))

-5 a-8 a = -13 a:
Answer: |  a (-13 a-12 b)

I think it's 91. 

9+1=10 

10x2=20 

We reverse 91 to 19

19 is one less than 20.

I am not sure though.

Hello !

A store sold a total of 125 car stereo systems and speakers in one week. The stereo systems sold for $104.95 and the speakers sold for $18.95. The sales from these two items totaled $6926.75. How many of each item were sold?

Let stereos=s

Let speakers=k

s+k =125

104.95s + 18.95k=6926.75

Solve the following system:
{k+s = 125
18.95 k+104.95 s = 6926.75

In the first equation, look to solve for s:
{k+s = 125
18.95 k+104.95 s = 6926.75

Subtract k from both sides:
{s = 125-k
18.95 k+104.95 s = 6926.75

Substitute s = 125-k into the second equation:
{s = 125-k
104.95 (125-k)+18.95 k = 6926.75

104.95 (125-k)+18.95 k = 18.95 k+(13118.8-104.95 k) = 13118.8-86. k:
{s = 125-k
13118.8-86. k = 6926.75

In the second equation, look to solve for k:
{s = 125-k
13118.8-86. k = 6926.75

13118.8-86. k = 52475/4-86 k and 6926.75 = 27707/4:
52475/4-86 k = 27707/4

Subtract 52475/4 from both sides:
{s = 125-k
-86 k = -6192

Divide both sides by -86:
{s = 125-k
k = 72

Substitute k = 72 into the first equation:
{s = 53
k = 72

Collect results in alphabetical order:
Answer: |  k = 72                     and                           s=53

5y=8-2

5y=6

6/5y=1.2

y=1.2

two+(9-6)*3:

2 + (3*3) =

2 + 9 =11

2,000,000,000,000x.05=100,000,000,000

what is 5% of 2 Trillion?

5/100 x (2 x 10^12) =1 x 10^11

To clarify:    cos(90° - x) = sin(x)

.

x = sin^-1(0.2588) ≈ 15°

The cosine of the complementary angle to x is always equal to the sine of x.  (Complementary angles sum to 90°).

Use the online chi-squared calculator at http://stattrek.com/online-calculator/chi-square.aspx 

Thank you Alan!

Sinh, tanh and cosh are hyperbolic funtions, you probably won't use them for a long time.

https://en.wikipedia.org/wiki/Hyperbolic_function

Sindh I think is a mistake of yours.

Rand probably stands for random number.  Maybe between 0 and 1.

2*2*2*3*5 = 120

.

[3 * 6 * 12 - 6] / 4   *  5   =

[18 *  12  - 6] / 4  * 5  =

[216 - 6 ] / 4  * 5 =

[210] / 4 * 5 =

[105/2] * 5  =

[525] / 2 =

262.5

Let us find the angle at Canton - angle NCE - of the triangle formed by  Canton, Elgin and Naples.....using the Law of Sines, we have

sin (angle NCE) / 500  = sin (46)/ 720

sin (angle NCE)  = 500sin(46)/ 720

arcsin (500 sin(46)/720) = angle NCE ≈ 30°

So....the angle at Elgin - angle CEN -   equals   [180 - 46 - 30] °  ≈ 104°

So....the bearing from Elgin to Canton is given by  [ 180 + (104 - 44)]°  ≈ 240°

cos^3 (2x)  = cos(2x)     subtract cos(2x) from each side

cos^3 (2x) - cos(2x) = 0      factor out cos(2x)

cos(2x)  [ cos^2 (2x) - 1 ] = 0

Setting both factors to 0 and solving, we have

cos(2x)  = 0

cos(x) = 0 at     x =   pi/2 , 3pi/2, 5pi/2 and at 7pi/2

Then cos(2x)   will = 0 when x =  pi/4 , 3pi/4, 5pi/4, 7pi/4

For the second factor, we have

cos^(2x) - 1  = 0    factor as a difference of squares

[cos (2x)  - 1] [ cos (2x) + 1]  =0

Setting the first factor to 0, we have

cos(2x) - 1  = 0   add  1 to both sides

cos(2x)  = 1  

cos(x)  = 1     when x = 0  and when x = 2pi

So .... cos(2x) will = 1 when x = 0  and x = pi

And for the last factor, we have

cos(2x) + 1  = 0       subtract 1 from both sides

cos(2x)  = -1

cos(x)  = -1    when x = pi    and when x = 3pi

So.......cos(2x)   will = 0   when x =  pi/2   and x =  3pi/2

So....the solutions are

x =0 , x =  pi/4 , x = pi/2 , x = 3pi/4 ,x = pi,  x= 5pi/4, x = 3pi/2, x = 7pi/4

Here's a graph :

https://www.desmos.com/calculator/5zuwwk5xwb

Every one of these can be transformed into the linear equation y= 2x + 1.....the behavior [ and definition] of the last two differs slightly from the first "parent" graph

Here's a graph  of the first one...it's the same graph as y = 2x + 1

Here's a graph of the second :

Notice that it's very similar to the first, except that it is not defined for any x less than or equal to 0 because an exponential can never be 0 or negative......thus, we might say that this graph is the first quadrant representation of the first one where x > 0

Here's the last one :

Note that this one is a "truncated" graph of the first....at t =0, we have the point (1,3).....then, as t increases from 0 to pi/2, the motion is back towards the y axis [an x axis, as well] until we get to the point (0, 1).....as t increases from pi/2 to pi......the motion proceeds to (-1, -1).....from pi to 3pi/2 the motion now proceeds back to (0,1).....and as t increases from 3pi/2 to 2pi, the motion proceeds back to the starting point of (1,3).....this oscillation continues infinitely.....

Hope that helps some.....!!!!

Did you mean 5 meters in meters per second? 

If so

5 meters/minute = 0.08333333333333 meter/second