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3 years ago

7 times a number is 8 less than the square of that number. Find the negative solution.

Mathematics

1 answer:

charle [14.2K]3 years ago

7 0

Answer:

-1

Step-by-step explanation:

The required relation is ...

7n = n^2 -8

0 = n^2 -7n -8 . . . . put in standard form

0 = (n -8)(n +1) . . . . factor

Solutions are n=8 and n=-1.

The negative solution is -1.

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X/7- y/5=1 solve for y

Usimov [2.4K]

Answer:

y = 5/7 x -5

Step-by-step explanation:

X/7- y/5=1

Multiply each side by 35 to clear the fractions

35(X/7- y/5) =1*35

5x - 7y = 35

Subtract 5x from each side

5x-5x-7y = -5x+35

-7y = -5x+35

Divide each side by -7

-7y/-7 = -5x/-7 +35/-7

y = 5/7 x -5

4 0

3 years ago

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Open image to see question

Agata [3.3K]

Answer:

Step-by-step explanation:

To start off this problem, we are given that the line AB is equal to the line CD. In addition to that, we are given that the line EF equally intersects line AB and line CD. This provides us proof that angle AGH is equivalent to angle DHG. From this information, we can solve this problem relatively easily.

Lets work with this equation:

$80 = 5x$

Next, divide 80 by 5.

$\frac{80}{5} =x$

$16 = x$

This means that x is equal to 16.

7 0

3 years ago

What's the answer to this question

frutty [35]

Step-by-step explanation:

there are several things to be considered to solve this.

the strategy is to caucuses the volume of the full "box", and then to deduct the 3-dimensional triangle that is "cut off" from the oil.

then we know the volume of the pool.

next step is to calculate the volume of a "box" with the same layout but is only 20 cm deep.

then we know how much volume can be pumped out in 30 minutes.

and then we divide the whole volume by that small volume to see how many 30-minues units are needed to empty the whole pool.

and then we transform the 30- minutes units into actual minutes or hours.

so, let's begin :

the whole box's volume is

2×1×1.4 = 2.8 m³

the volume of the 3-D triangle we need to subtract is the area of the triangle × width of the pool (this pool width is the height of the 3-D triangle).

2×(1.4 - 0.6) × 1 / 2 = 2×0.8 × 1 / 2 = 1.6/2 = 0.8 m³

so, the volume of the pool is

2.8 - 0.8 = 2 m³

now, how much volume can the pump eliminate in 30 minutes ?

the content of a box

1×2×0.2 = 0.4 m³

as 20 cm = 0.2 m

so, the pump pumps out 0.4 m³ in 30 minutes.

and we need to empty 2 m³.

that means we need

2 / 0.4 = 5

30-minues units = 5×30 = 150 minutes = 2.5 hours.

Colin has to wait 2.5 hours (150 minutes) to empty the complete pool.

6 0

3 years ago

What are the slope and why intercept shown on the graph below

viktelen [127]

Hello!

Let's start by finding the slope of the line. You can calculate the slope by dividing the change in y-values by the change in x-values using the following formula:

$\frac{ y_{1}- y_{2} }{ x_{1} - x_{2} }$

The plotted coordinates are (0, 5) and (4, -5); let's plug those into the formula:

$\frac{5(-5)}{0-4}$

Simplify:

$\frac{5+5}{-4}$

$\frac{10}{-4}$

$\frac{-5}{2}$

The slope is $\frac{-5}{2}$ .

Now, the y-intercept is where the line intersects the y-axis, or when x equals 0. x equals 0 when y equals 5, so the y-intercept is 5.

I hope this helps!

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3 years ago

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Please answer this correctly

nikklg [1K]

Answer:

63.59

Step-by-step explanation:

If the perimeter is 32.13, that means it is equal to

2r + 2πr/4 = 32.13

Solving this for r we get 9

Now, we can find the area, which is 3.14*r^2 / 4. Assuming pi to be 3.14 again, we get 63.585. Rounding this to the nearest hundredth, we get 63.59

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3 years ago