All categories

2 years ago

Solve the system of equations 4x equations. 8y = -8 and 5x-9y = -7 by combining the

Mathematics

1 answer:

statuscvo [17]2 years ago

4 0

Answer:

x=−16/5

and y=−1

Step-by-step explanation:

You might be interested in

Consider the line 5x-8y=8 what is the slope of a line perpendicular to this line what is the slope of a line parallel to this li

Sophie [7]

$\text{Let}\ k:y=m_1x+b_1\ \text{and}\ l:y=m_2x+b_2,\ \text{then}\\\\l\ \perp\ k\iff m_1m_2=-1\to m_2=-\dfrac{1}{m_1}\\\\l\ \parallel\ k\iff m_1=m_2\\\\\text{Convert the equation to the slope-intercept form}\ y=mx+b.\\\\5x-8y=8\qquad\text{subtract}\ 5x\ \text{from both sides}\\\\-8y=-5x+8\qquad\text{divide both sides by (-8)}\\\\y=\dfrac{5}{8}x-1\to m_1=\dfrac{5}{8}\\\\perpendicular:\ m_2=-\dfrac{1}{\frac{5}{8}}=-\dfrac{8}{5}\\\\parallel:\ m_2=\dfrac{5}{8}$

8 0

2 years ago

Determine the value of x and y and the measure of

artcher [175]

You need to finish the question

6 0

2 years ago

Where are the x-intercepts for f(x) = −4cos(x − pi over 2) from x = 0 to x = 2π?

yKpoI14uk [10]

Recall that to get the x-intercepts, we set the f(x) = y = 0, thus

$\bf \stackrel{f(x)}{0}=-4cos\left(x-\frac{\pi }{2} \right)\implies 0=cos\left(x-\frac{\pi }{2} \right)
\\\\\\
cos^{-1}(0)=cos^{-1}\left[ cos\left(x-\frac{\pi }{2} \right) \right]\implies cos^{-1}(0)=x-\cfrac{\pi }{2}
\\\\\\
x-\cfrac{\pi }{2}=
\begin{cases}
\frac{\pi }{2}\\\\
\frac{3\pi }{2}
\end{cases}$

$\bf -------------------------------\\\\
x-\cfrac{\pi }{2}=\cfrac{\pi }{2}\implies x=\cfrac{\pi }{2}+\cfrac{\pi }{2}\implies x=\cfrac{2\pi }{2}\implies \boxed{x=\pi }\\\\
-------------------------------\\\\
x-\cfrac{\pi }{2}=\cfrac{3\pi }{2}\implies x=\cfrac{3\pi }{2}+\cfrac{\pi }{2}\implies x=\cfrac{4\pi }{2}\implies \boxed{x=2\pi }$

3 0

2 years ago

The school librarian, Mr. Marker, knows the library has 1,400 books but wants to reorganize how the books are displayed on the s

kipiarov [429]

Answer:

200 resource books

800 fiction books

400 nonfiction books

Step-by-step explanation:

Let's define x as the amount of resource books that are in the library. As he has four times as many fiction books as resource books, that means he has 4*x fiction books.

We also know he has half as many nonfiction books as fiction books, that is 1/2*4*x = 2*x nonfiction books.

We just need to find out the value of x.

We know there are 1,400 books in total and there are just 3 types of books. Therefore, if we sum all of them, we get the 1,400.

Written in math language, that is

x + 4x + 2x = 1,400

7x = 1,400

We divide by 7 on both sides and we get

7/7x = 1,400/7

x = 200

Now we replace the x with 200 to know how many books he has of each type:

Resource books = x = 200

Fiction books = 4*x = 4*200 = 800

Nonfiction books = 2*x = 2*200 = 400

Therefore, there are 200 resource books, 800 fiction books and 400 nonfiction books in the library.

The tape diagram is attached as an image.

8 0

2 years ago

Evaluate the integral. (remember to use absolute values where appropriate. Use c for the constant of integration.) 5 cot5(θ) sin

ozzi

$I=5\int \frac{cos^{4}\theta }{sin\theta }\times cos\theta d\theta \\\\I=5\int \left ( 1-sin^{2}\theta \right )^{2}\times \frac{cos\theta }{sin\theta }d\theta \\put\ \sin\theta =t\\\\dt=cos\theta d\theta \\\\I=5\int\frac{t^{4}+1-2t^{2}}{t}dt\ \ \ \ \ \ \ \ \ \ \because (a-b)^2=a^2+b^2-2ab\\\\I=5\left ( \int t^{3}dt + \int \frac{1}{t} -2\int t \right )dt$

by using the integration formula

we get,

$\\I=5\left ( \frac{t^{4}}{4} +logt -t^{2}\right )\\\\I=\frac{5}{4}t^{4}+5\log t-5t^{2}+c$

now put the value of t=\sin\theta in the above equation

we get,

$\int 5\cot^5\theta \sin^4\theta d\theta=\frac{5}{4}sin^{4}\theta+5\log \sin\theta - 5sin^{2} \theta+c$

hence proved

7 0

2 years ago