All categories

3 years ago

A trader buys 30 shirts for #x each. He sellsthem all for #y each. What is his profit

1 answer:

7 0

If he buys 30 for x amount and sells them for y then you would take y and subtract 30x and your left with the answer = y-30x.

You might be interested in

What is 1,030 times 12

almond37 [142]

your question answer is 12360

6 0

3 years ago

Read 2 more answers

Now there is a door whose height is more than its width by 6 chi 8 cun. The distance between the [opposite] corners is 1 zhang.

Kaylis [27]

Answer:

height: 9 chi 6 cun
width: 2 chi 8 cun

Step-by-step explanation:

The factor-of-ten relationship between the different units means we can combine the numbers in decimal fashion. If 1 unit is 1 zhang, then 1 chi is 0.1 zhang and 1 cun is 0.01 zhang. Hence 6 chi 8 cun is 0.68 zhang.

Let x and y represent the width and height, respectively. In terms of zhang, we have ...

y - x = 0.68

x^2 +y^2 = 1^2

Substituting y = 0.68 +x into the second equation gives ...

x^2 + (x +0.68)^2 = 1

2x^2 +1.36x - 0.5376 = 0 . . . . . eliminate parentheses, subtract 1

Using the quadratic formula, we have ...

x = (-1.36 ±√(1.36^2 -4(2)(-0.5376)))/(2·2) = (-1.36 ±√6.1504)/4

x = 0.28 . . . . . the negative root is of no interest

y = 0.28 +0.68 = 0.96

In units of chi and cun, the dimensions are ...

height: 9 chi 6 cun

width: 2 chi 8 cun

6 0

4 years ago

Read 2 more answers

Graph the given inequality. y ≤ 4 – | x |

Brilliant_brown [7]

Answer:

The graph is included in the attached pictures

Step-by-step explanation:

The graph for y=4-|x| is shown in the attached picture, the inequality tell us that the region is located below that particular graph including the function, hence you have the second attached picture

6 0

3 years ago

NEED THE ANSWER ASAP, PLEASE HELP!! What are the coordinates of the focus of the parabola?

qwelly [4]

Answer:

Vertex is (-8, 4) not one of the answers offered!

Step-by-step explanation:

Factor -1/8 out of the first two terms. Leave a space inside parentheses in which to add a number.

$y=-\frac{1}{8}(x^2 + 16x + \text{-----})-4$

Complete the square by squaring half the coefficient of x and adding it in the space.

$(\frac{16}{2})^2=64$

Add 64 in the space you made, then compensate for that at the end of the expression by subtracting $-\frac{1}{8}(64)=-8$

$y=-\frac{1}{8}(x^2+16x+64)-4+8\\y=-\frac{1}{8}(x+8)^2+4$

The x-coordinate of the vertex is the opposite of +8, the number inside the parentheses. The y-coordinate of the vertex is the number at the end of the expression.

V(-8, 4)

8 0

3 years ago

1. Let f(x, y) be a differentiable function in the variables x and y. Let r and θ the polar coordinates,and set g(r, θ) = f(r co

Olenka [21]

Answer:

$g_{r}(\sqrt{2},\frac{\pi}{4})=\frac{\sqrt{2}}{2}\\$

Step-by-step explanation:

First, notice that:

$g(\sqrt{2},\frac{\pi}{4})=f(\sqrt{2}cos(\frac{\pi}{4}),\sqrt{2}sin(\frac{\pi}{4}))\\$

$g(\sqrt{2},\frac{\pi}{4})=f(\sqrt{2}(\frac{1}{\sqrt{2}}),\sqrt{2}(\frac{1}{\sqrt{2}}))\\$

$g(\sqrt{2},\frac{\pi}{4})=f(1,1)\\$

We proceed to use the chain rule to find $g_{r}(\sqrt{2},\frac{\pi}{4})$ using the fact that $X(r,\theta)=rcos(\theta)\ and\ Y(r,\theta)=rsin(\theta)$ to find their derivatives:

$g_{r}(r,\theta)=f_{r}(rcos(\theta),rsin(\theta))=f_{x}( rcos(\theta),rsin(\theta))\frac{\delta x}{\delta r}(r,\theta)+f_{y}(rcos(\theta),rsin(\theta))\frac{\delta y}{\delta r}(r,\theta)\\$

Because we know $X(r,\theta)=rcos(\theta)\ and\ Y(r,\theta)=rsin(\theta)$ then:

$\frac{\delta x}{\delta r}=cos(\theta)\ and\ \frac{\delta y}{\delta r}=sin(\theta)$

We substitute in what we had:

$g_{r}(r,\theta)=f_{x}( rcos(\theta),rsin(\theta))cos(\theta)+f_{y}(rcos(\theta),rsin(\theta))sin(\theta)$

Now we put in the values $r=\sqrt{2}\ and\ \theta=\frac{\pi}{4}$ in the formula:

$g_{r}(\sqrt{2},\frac{\pi}{4})=f_{r}(1,1)=f_{x}(1,1)cos(\frac{\pi}{4})+f_{y}(1,1)sin(\frac{\pi}{4})$

Because of what we supposed:

$g_{r}(\sqrt{2},\frac{\pi}{4})=f_{r}(1,1)=-2cos(\frac{\pi}{4})+3sin(\frac{\pi}{4})$

And we operate to discover that:

$g_{r}(\sqrt{2},\frac{\pi}{4})=-2\frac{\sqrt{2}}{2}+3\frac{\sqrt{2}}{2}$

$g_{r}(\sqrt{2},\frac{\pi}{4})=\frac{\sqrt{2}}{2}$

and this will be our answer

3 0

3 years ago

A trader buys 30 shirts for #x each. He sellsthem all for #y each. What is his profit​

A trader buys 30 shirts for #x each. He sellsthem all for #y each. What is his profit