Find the value of n in the following

There are 13 books on a shelf. 6 of these books are new. (a) What is the ratio of new books to used books? (b) What is the ratio

Drupady [299]

If 6 of the 13 books are new, then 7 of them are used. The ratio of new (6) to used (7) is

6:7 or 6/7

Ratio of all books (13) to used books (7) is

13:7 or 13/7

7 0

3 years ago

Read 2 more answers

9!-4!(5!) How do i solve?

Lemur [1.5K]

To simply the expression,we should remember an ! in math represents every number (til 1) before that one multiplied or "the product of the integers from 1 to n"

So now that we have the definitions we can simplify by finding the values of each:

(9x8x7x6x5x4x3x2x1)-(4x3x2x1)(5x4x3x2x1)

After simplifying this will equal to 3600

6 0

3 years ago

Can someone help me to find length CD

uysha [10]

Answer:

CD = 3.602019190339

Step-by-step explanation:

CD = DA - CA

DA = DB×Cos(29) = 18.7×cos(29) = 16.355388523507

BA = BA×cos(43) = 18.7×cos(43) = 13.676314220278

CA = BA÷tan(47) = 13.676314220278÷tan(47) = 12.753369333168

Then

CD = 16.355388523507 - 12.753369333168 = 3.602019190339

7 0

3 years ago

PLEASE HELP ASAP!!! CORRECT ANSWER ONLY PLEASE!!!

Kitty [74]

Answer: (-2, 5) and (2, -3)

<u>Step-by-step explanation:</u>

Graph the line y = -2x + 1 (which is in y = mx + b format) by plotting the y-intercept (b = 1) on the y-axis and then using the slope (m = -2) to plot the second point by going down 2 and right 1 unit from the first point:

y - intercept = (0, 1) 2nd point = ( -1, 1).

Graph the parabola y = x² - 2x - 3 by first plotting the vertex and then plotting the y-intercept (or some other point):

$y = x^2-2x-3\quad \rightarrow \quad a=1,\ b=-2,\ c=-3\\\\\text{axis of symmetry:}\ x = \dfrac{-b}{2a}\ \longrightarrow \ x=\dfrac{-(-2)}{2(1)}=\dfrac{2}{2}=1\\\\\text{y-value of vertex:}\ f(1) = (1)^2-2(1)-3\quad \longrightarrow \quad y = 1 - 2 - 3=-4\\\\\text{y-intercept:}\ f(0)= (0)^2-2(0)-3\ \longrightarrow \ y=0 - 0 - 3 = -3 \\$

vertex = (1, -4) 2nd point (y-intercept) = (0, -3)

<em>see attached</em> - the graphs intersect at two points: (-2, 5) and (2, -3)

8 0

3 years ago

A developer wants to enclose a rectangular grassy lot that borders a city street for parking. If the developer has 220 feet of f

MrRa [10]

Answer:

6050 square feet

Step-by-step explanation:

Based on the diagram attached, the area which the available fencing can enclose will measure X x Y feet. As the total length of fencing available is 220 feet, the fenced perimeter must equal 220 feet

$Y + 2X = 220$

$Y = 220 - 2X$

Area of a rectangle is determined by multiplying the length of perpendicular sides:

$Area = X*Y$

$Area = X(220 - 2X)$

$Area = 220X - 2X^{2}$

The derivative of an equation determines the slope at any given point of that equation. At the maximum or minimum point of the equation, the slope will be zero. Therefore, differentiating the equation for area and equating it to zero will give the value of X where the area is maximum.

A simple variable can be differentiated using below concept:

$f(a) = a^{b}$