All categories

3 years ago

Solve x/7-x=2x for x

Mathematics

2 answers:

Zanzabum3 years ago

6 0

The answer would be 7-x=x

elixir [45]3 years ago

5 0

X = 5 because 7-2 doesn't equal 2 that equals 5 7-3=4 so it can't be that 7-4=3 it can't that either and 7-5=2 so the correct answer is 5

You might be interested in

a volley ball player servers the ball. The ball follows a path given by the equation y=-0.01x^2+0.5x+3 where x and y are measure

dolphi86 [110]

Answer:

(a)

Distance from player should be 13.82 feet or 36.2 feet

(b)

The ball will go over the net

Step-by-step explanation:

we are given

The ball follows a path given by the equation

$y=-0.01x^2+0.5x+3$

where

x and y are measured in feet and the origin is on the court directly below where the player hits the ball

(a)

net height is 8 ft

so, we can set y=8

and then we can solve for x

$8=-0.01x^2+0.5x+3$

$8\cdot \:100=-0.01x^2\cdot \:100+0.5x\cdot \:100+3\cdot \:100$

$800=-x^2+50x+300$

$-x^2+50x-500=0$

$x^2-50x+500=0$

we can use quadratic formula

$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

$x=\frac{-50\pm \sqrt{50^2-4\left(-1\right)\left(-500\right)}}{2\left(-1\right)}$

$x=5\left(5-\sqrt{5}\right),\:x=5\left(5+\sqrt{5}\right)$

$x=13.82,x=36.2$

So, distance from player should be 13.82 feet or 36.2 feet

(b)

we can plug x=30 and check whether y=8 ft

$y=-0.01(30)^2+0.5(30)+3$

$y=9ft$

we know that

height of net is 8 ft

so, the ball will go over the net

5 0

3 years ago

Hector is dividing students into groups for an HR wants to divide the boys and girls so that each group has the same number of t

Roman55 [17]

Answer:

7 groups, 3 boys and 8 girls

Step-by-step explanation:

Let total number of groups be $x$

and total hikers in one group be $y$

if number of girls and boys in every group is same, then

$\frac{21}{x} + \frac{56}{x} = y$

$\frac{21 + 56}{x} = y\\x*y = 77$ ....(1)

from (1) $x$ will either be 11 or 7

for $x = 11$ the values won't be real.

For $x = 7\\y = \frac{77}{7} \\y = 11$

so there will be 7 groups with 11 hikers in each groups and every group will have $\frac{21}{7} = 3$ boys and $\frac{56}{7} = 8$ girls

6 0

3 years ago

Pure copper was mixed with a 10% copper alloy to produce an alloy thát was 25% copper. How much of the pure copper and how much

lora16 [44]

Answer:

6kg pure copper and 30 kg 10% copper was mixed to give 36kg of 25% alloy

Step-by-step explanation:

Here, we want to produce 36 kg of 25% alloy

Let the Pure copper be x kg while 10% alloy be y kg

Pure copper is simply 100% copper

Thus;

x + y = 36 •••••(i)

Then;

100% of x + 10% of y = 25% of 36

= x + 0.1y = 9 •••••• ii)

From i x = 36-y

from ii, x = 9-0.1y

Equate both x

36-y = 9-0.1y

36-9 = 0.1y + y

0.9y = 27

y = 27/0.9

y = 30

x = 36-y

x = 36-30

x = 6 kg

8 0

3 years ago

For his phone service, Charlie pays a monthly fee of $ 18 , and he pays an additional $ 0.06 per minute of use. The least he has

schepotkina [342]

Answer:

Charlie has used his phone in a month for at least 1404 minutes

Step-by-step explanation:

In order to solve this problem, we must first determine what will our variable be and what it will represent.

Let's say our variable is x and it will represent the number of minutes Charlie has used his phone.

After we set our variable up, we can set our equation up. The problem states that Charlie will pay a monthly fee of $18 and additional $0.06 per minute of use. The $18 is what is called a fixed cost and the $0.06 is the variable cost, which will depend on our variable x (the number of minutes spent). Taking this into account we can build an inequality that will represent the amount of money spent in a month, which will look like this:

$18+0.06x\geq 102.24$