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3 years ago

A blender was originally sold for $90 and has been marked

Mathematics

2 answers:

ale4655 [162]3 years ago

5 0

Answer:

88%

Step-by-step explanation:

From the question given above, the following data were obtained:

Original amount = $ 90

Discounted amount = $ 79.20

Percentage of discount =?

Let the percentage of discount be y %

Thus, we can obtain the value of y as follow:

y /100 × 90 = 79.20

90y /100 = 79.20

Cross multiply

90y = 100 × 79.20

90y = 7920

Divide both side by 90

y = 7920/90

y = 88

Thus, the percentage discount of the blender is 88%

Ivenika [448]3 years ago

3 0

Answer:

Step-by-step explanation:

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A pine tree is 64 feet 3 inches tall. How many inches tall is the pine tree?

Sindrei [870]

Answer:

3 inches you are right

Step-by-step explanation:

4 0

3 years ago

A parcel delivery service will deliver a package only if the length plus girth (distance around) does not exceed 84 inches. (A

Kisachek [45]

Answer:

A. 14x14x28

B. The maximum volume is 5488 cuibic inches

Step-by-step explanation:

The problem states that the box has square ends, so you can express volume with:

$v=x^{2} y$

Using the restriction stated in the problem to get another equation you can substitute in the one above:

$4x+y=84\\\\$

Substituting y whit this equation gives:

$v=x^{2} (84-4x)\\\\v=84x^{2} -4x^{3}$

Now find the limit of x:

$\frac{84x^{2}-4x^{3}}{dx}=168x-12x^{2}\\\\x=\frac{168}{12}=14$

Find the length:

$y=84-4(14)=28$

You can now calculate the maximum volume:

$v=(14)^{2}(28)= 5488$

6 0

3 years ago

How many eighth-size parts do you need to model 3/4

Molodets [167]

8 divided by 2 is 4, so multiply 3/4 by 2, 6/8, than you have your answer, 6.

8 0

3 years ago

**Solve by Elimination 3 + 2x - y = 0 -3-7y = 10x 7) x = 8) y =

timofeeve [1]

Answer:

Explanation:

3 + 2x - y = 0
Or 2x - y = -3 (1)

-3-7y = 10x
Or -10x - 7y = 3 (2)

2x - y = -3 (1)
-10x - 7y = 3 (2)
———————

Multiply 5 to (1)

5(2x - y = -3)
-10x - 7y = 3
———————
10x - 5y = -15
-10x - 7y = 3
———————
-12y = -12
y = -12/-12
y = 1

Plug y value in (1)

2x - 1 = -3
2x = -3 + 1
2x = -2
x = -2/2 = -1

Therefore, x = -1 and y = 1

7 0

2 years ago

For each of the following vector fields F , decide whether it is conservative or not by computing curl F . Type in a potential f

Phantasy [73]

The key idea is that, if a vector field is conservative, then it has curl 0. Equivalently, if the curl is not 0, then the field is not conservative. But if we find that the curl is 0, that on its own doesn't mean the field is conservative.

$\mathrm{curl}\vec F=\dfrac{\partial(5x+10y)}{\partial x}-\dfrac{\partial(-6x+5y)}{\partial y}=5-5=0$

We want to find $f$ such that $\nabla f=\vec F$ . This means

$\dfrac{\partial f}{\partial x}=-6x+5y\implies f(x,y)=-3x^2+5xy+g(y)$

$\dfrac{\partial f}{\partial y}=5x+10y=5x+\dfrac{\mathrm dg}{\mathrm dy}\implies\dfrac{\mathrm dg}{\mathrm dy}=10y\implies g(y)=5y^2+C$

$\implies\boxed{f(x,y)=-3x^2+5xy+5y^2+C}$

so $\vec F$ is conservative.

$\mathrm{curl}\vec F=\left(\dfrac{\partial(-2y)}{\partial z}-\dfrac{\partial(1)}{\partial y}\right)\vec\imath+\left(\dfrac{\partial(-3x)}{\partial z}-\dfrac{\partial(1)}{\partial z}\right)\vec\jmath+\left(\dfrac{\partial(-2y)}{\partial x}-\dfrac{\partial(-3x)}{\partial y}\right)\vec k=\vec0$

Then

$\dfrac{\partial f}{\partial x}=-3x\implies f(x,y,z)=-\dfrac32x^2+g(y,z)$

$\dfrac{\partial f}{\partial y}=-2y=\dfrac{\partial g}{\partial y}\implies g(y,z)=-y^2+h(y)$

$\dfrac{\partial f}{\partial z}=1=\dfrac{\mathrm dh}{\mathrm dz}\implies h(z)=z+C$

$\implies\boxed{f(x,y,z)=-\dfrac32x^2-y^2+z+C}$

so $\vec F$ is conservative.

$\mathrm{curl}\vec F=\dfrac{\partial(10y-3x\cos y)}{\partial x}-\dfrac{\partial(-\sin y)}{\partial y}=-3\cos y+\cos y=-2\cos y\neq0$

so $\vec F$ is not conservative.

$\mathrm{curl}\vec F=\left(\dfrac{\partial(5y^2)}{\partial z}-\dfrac{\partial(5z^2)}{\partial y}\right)\vec\imath+\left(\dfrac{\partial(-3x^2)}{\partial z}-\dfrac{\partial(5z^2)}{\partial x}\right)\vec\jmath+\left(\dfrac{\partial(5y^2)}{\partial x}-\dfrac{\partial(-3x^2)}{\partial y}\right)\vec k=\vec0$

Then

$\dfrac{\partial f}{\partial x}=-3x^2\implies f(x,y,z)=-x^3+g(y,z)$

$\dfrac{\partial f}{\partial y}=5y^2=\dfrac{\partial g}{\partial y}\implies g(y,z)=\dfrac53y^3+h(z)$

$\dfrac{\partial f}{\partial z}=5z^2=\dfrac{\mathrm dh}{\mathrm dz}\implies h(z)=\dfrac53z^3+C$

$\implies\boxed{f(x,y,z)=-x^3+\dfrac53y^3+\dfrac53z^3+C}$

so $\vec F$ is conservative.

4 0

4 years ago