Which expression is equivalent to 25? 2 + 2 + 2 + 2 + 2 5+5 0 2.2.2.2.2 5.5 DONE

3x+y=8________(1) and x²+xy=6________(2) solve this

romanna [79]

Answer:

In first equation if we put the value of x and y (x=2,y=2)than,

3x+y=8

3×x+y=8

3×2+2=8

6+2=8

8=8

in second equation the value of x=2,y=1

x2+xy=6

x2+x×y=6

4+2×1=6

4+2=6

6=6

6 0

2 years ago

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Points A, B, and C are collinear, and B lies

olya-2409 [2.1K]

Answer:

BC = 30

Step-by-step explanation:

If the three points are collinear, it means they lie on the same straight line.

Now B lies between A and C

By mathematical convention;

AC = AB + BC

This means;

48 = 2x + 2 + 3x + 6

48 = 5x + 8

48-8 = 5x

5x = 40

x = 40/5

x = 8

From the question BC = 3x + 6

Substitute the value of x; 3(8) + 6 = 24 + 6 = 30

3 0

2 years ago

How many times does 1 and 7/8 go into at least nine but less than 10?

Gelneren [198K]

Should be four times to get in between 9 and 10

7 0

2 years ago

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A metal cylinder can with an open top and closed bottom is to have volume 4 cubic feet. Approximate the dimensions that require

Aleksandr-060686 [28]

Answer:

$r\approx 1.084\ feet$

$h\approx 1.084\ feet$

$\displaystyle A=11.07\ ft^2$

Step-by-step explanation:

Optimizing With Derivatives

The procedure to optimize a function (find its maximum or minimum) consists in :

Produce a function which depends on only one variable
Compute the first derivative and set it equal to 0
Find the values for the variable, called critical points
Compute the second derivative
Evaluate the second derivative in the critical points. If it results positive, the critical point is a minimum, if it's negative, the critical point is a maximum

We know a cylinder has a volume of 4 $ft^3$ . The volume of a cylinder is given by

$\displaystyle V=\pi r^2h$

Equating it to 4

$\displaystyle \pi r^2h=4$

Let's solve for h

$\displaystyle h=\frac{4}{\pi r^2}$

A cylinder with an open-top has only one circle as the shape of the lid and has a lateral area computed as a rectangle of height h and base equal to the length of a circle. Thus, the total area of the material to make the cylinder is

$\displaystyle A=\pi r^2+2\pi rh$

Replacing the formula of h

$\displaystyle A=\pi r^2+2\pi r \left (\frac{4}{\pi r^2}\right )$

Simplifying

$\displaystyle A=\pi r^2+\frac{8}{r}$

We have the function of the area in terms of one variable. Now we compute the first derivative and equal it to zero

$\displaystyle A'=2\pi r-\frac{8}{r^2}=0$

Rearranging

$\displaystyle 2\pi r=\frac{8}{r^2}$

Solving for r

$\displaystyle r^3=\frac{4}{\pi }$

$\displaystyle r=\sqrt[3]{\frac{4}{\pi }}\approx 1.084\ feet$

Computing h

$\displaystyle h=\frac{4}{\pi \ r^2}\approx 1.084\ feet$

We can see the height and the radius are of the same size. We check if the critical point is a maximum or a minimum by computing the second derivative

$\displaystyle A''=2\pi+\frac{16}{r^3}$

We can see it will be always positive regardless of the value of r (assumed positive too), so the critical point is a minimum.

The minimum area is

$\displaystyle A=\pi(1.084)^2+\frac{8}{1.084}$

$\boxed{ A=11.07\ ft^2}$

8 0

2 years ago

How do I find the slope of the line through (–9, –10) and (–2, –5)?

storchak [24]

Answer:
slope of line is 5/7

Explanation:
The slope of the line can be calculated using the following rule:
slope = $\frac{y2-y1}{x2-x1}$

The given points are:
(-9,-10) which represent (x1,y1)
(-2,-5) which represent (x2,y2)

Substitute with the points in the above equation to get the slope as follows:
slope = $\frac{-5-(-10)}{-2-(-9)}$ = 5/7

Hope this helps :)

4 0

3 years ago

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