All Answers 358184 Answers

5n + 3f = 15.5 (1)

4n + 4f = 14 (2)

(1) * 4 = (4)

(2) * 3 = (3)

Then we get:

12n + 12n = 42 (3)

20n + 12f = 62 (4)

Subtract

8n = 20

n = 5/2 

4(5/2) + 4f = 14

10 + 4f = 14

4f = 4

f = 1 

The cost of one noteboook and one folder will be 5/2 + 1 = $3.50 

Call the original  number of students, S...and the number of girls  = .60S

Total students  after 20 boys arrive = S + 20

Also:

Number of  girls divided by total number of students  =  58%

.6S  / ( S + 20 )  =   .58    multiply both sides by  S +  20

.6S  = .58( S + 20 )

.6S  = .58S + 11.6   subtract  .58S from  both sides

.02S = 11.6   divide both sides  by .02

S  = 11.6 / .02 =    580

So...the total number of students = 580 + 20  = 600 

B 

2*5 = 10

1.75 * 2 * 1/2 = 1.75

(8-6.75)2 * 1/2 = 8 - 6.75 = 1.25

10 + 1.75 + 1.25 = 13

120,000(1.2)^15 = 1848842.589   Wow, thats alot!

@CPhill. Oops, I calculated the slope wrong.

Formula: 

y = a(1 + r)^x

1.)

2000(1 + 0.04)^3 = 2249.728 = $2249.73

2.)

2000(1.04)^18 = 4051.633031...

3.)

2000(1.04)^6 = 2530.638037... So 6.

4.) I think you already answered it.

13.5*100 = 1350 liters of water.

1350/375 = 3.6 days.

ty! :))

Leg 1 = 8/2 = 4

Leg 2 = 4sqrt(3)

There are 3 triangles in the diagram.

The second smallest triangle has a 90° and 30°, meaning the last angle is 60°; thus the triangle is a 30-60-90 triangle.

The smallest triangle is a 30-60-90 triangle as it has a 90° angle, and a 90 - 60 = 30° angle. The last angle is therefore 60°, meaning the triangle is also a 30-60-90 triangle.

The large triangle has a 90° and 45° angle, meaning the last angle is 45°, indicating a 45-45-90 triangle.

The side opposite of the 30° angle is:

7*2 = 14

The vertical side of the largest triangle is:

14*2 = 28

Therefore x =

28 * √2 = 28√2

We can form a right triangle  wirh  legs of   4  and (7 - 2)  = 5

Then  

x = sqrt  [ 4^2  + 5^2  ]  =  sqrt [  16 + 25 ] =  sqrt [ 41 ]  = 6.4

7 / sin30º = 14

7 / 14 = 14 / s           ( "s" is a side of a largest triangle)

x = sqrt(s² + s²)

x = 7√32

We  have  the  points  ( - 1, 5)  abd  ( 0 , -5)

Slope  =   ( -5 - 5)  / ( 0 - - 1)  =   -10 / 1   =  - 10

Using the slope and  ( 0. -5)  we  have

y  = -10 ( x - 0)  - 5

y  =  -10x -  5

Good luck. :))))

=^._.^=

7^2  - x^2   =  4^2  + 4^2

49  - x^2  =   32

x^2  = 49 - 32

x^2  = 17

x =  sqrt (17)  ≈   4.1

x = 4 * 6 = 24

wrong

J  +   (2J +4)  = 31

3J = 27

J = 9 CDs

Ok here:

Slope:

-1/10

y = -1/10 x + a

-1 = -1/2 + a

a = 1/2 - 1 = -1/2

y = -(1/20)x - (1/2)

SinC = 32/40 = 8/10 = 4/5

thats wrong 

Setting $y$ to zero, we get the quadratic \[-16t^2 - 60t + 54 = 0.\]Dividing both sides by $-2,$ we get \[8t^2 + 30t - 27 = 0.\]This quadratic factors as $(4t - 3)(2t + 9) = 0.$ As $t$ must be positive, we can see that $t = \frac{3}{4} = \boxed{0.75}.$ 

Its actully 0.75. 

3.5 * 2.5 + 3.5 * 1.2 * 0.5 = 8.75 + 2.1 = 10.85