It took Freddy 1/2 hr to paint 1/5 of a fence. How long in minutes will it take him to paint the whole fence?

Consider the following division of polynomials.

Bond [772]

$x^4=x^2\cdot x^2$ . Multiplying the denominator by $x^2$ gives

$x^2(x^2+2x+8)=x^4+2x^3+8x^2$

Subtracting this from the numerator gives a remainder of

$(x^4+x^3+7x^2-6x+8)-(x^4+2x^3+8x^2)=-x^3-x^2-6x+8$

$-x^3=-x\cdot x^2$ . Multiplying the denominator by $-x$ gives

$-x(x^2+2x+8)=-x^3-2x^2-8x$

and subtracting this from the previous remainder gives a new remainder of

$(-x^3-x^2-6x+8)-(-x^3-2x^2-8x)=x^2+2x+8$

This last remainder is exactly the same as the denominator, so $x^2+2x+8$ divides through it exactly and leaves us with 1.

What we showed here is that

$\dfrac{x^4+x^3+7x^2-6x+8}{x^2+2x+8}=x^2-\dfrac{x^3+x^2+6x-8}{x^2+2x+8}$

$=x^2-x+\dfrac{x^2+2x+8}{x^2+2x+8}$

$=x^2-x+1$

and this last expression is the quotient.

To verify this solution, we can simply multiply this by the original denominator:

$(x^2+2x+8)(x^2-x+1)=x^2(x^2-x+1)+2x(x^2-x+1)+8(x^2-x+1)$

$=(x^4-x^3+x^2)+(2x^3-2x^2+2x)+(8x^2-8x+8)$

$=x^4+x^3+7x^2-6x+8$

which matches the original numerator.

3 0

3 years ago

Read 2 more answers

A soup can has a diameter of 8 cm and a height of 12 cm. What is the volume of the soup can? Use 3.14 for Pi. A cylinder has a h

Alik [6]

Answer:

602.88

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Suppose A and B represent two different school populations where A > B and A and B must be greater than 0. Which of the follo

Ulleksa [173]

We can reject the last one: subtracting a non-zero value will result in a smaller value.

So now we have:

<span>2(A + B)
(A + B)2
A2 + B2

If all of them are mulptiplications, then they are all equivalent!

I mean by this, if what you meant is this:

</span>
<span>2*(A + B)
(A + B)*2
A*2 + B*2

If there is no sign, then the multiplication sign is implicit,

and all of these expressions say exactly the same: two of A and two of B.
</span>

6 0

3 years ago

The question is on the picture included

Alexxx [7]

The next step is to draw an arc with center E.

4 0

3 years ago

A ladder 10 ft long rests against a vertical wall. If the bottom of the ladder slides away from the wall at a rate of 0.8 ft/s,

shusha [124]

Answer:

-0.133 radians/s is the angle between the ladder and the ground changing when the bottom of the ladder is 8 ft from the wall.

Step-by-step explanation:

Let

x= distance between the wall and ladder

Ф = angle between the ladder and ground

The rate of change is: dx/dt = 0.8 ft/s

We need to find dФ/dt when x = 8 ft/s

From the triangle in the figure we see that:

cos Ф = x/10

=> x = 10 cosФ

Now, the rate of change will be

d(x)/dt = d/dt (10cosФ)

dx/dt = -10 sin Ф dФ/dt

dx/dt = 0.8 (given)

to find dФ/dt

we need to find sin Ф when x = 8

By Pythagoras theorem

(hypotenuse)^2 = (Perpendicular)^2+(base)^2

(10)^2 = (8)^2+ (Perpendicular)^2

100 = 64 + (Perpendicular)^2

=> (Perpendicular)^2 = 100-64

(Perpendicular)^2 = 36

Perpendicular = 6

sin Ф = Perpendicular/hypotenuse

sin Ф = 6/10 = 3/5

Putting values in:

dx/dt = -10 sin Ф dФ/dt

0.8 = -10(3/5) dФ/dt

0.8 = -6 dФ/dt

=> dФ/dt = 0.8 / -6

dФ/dt = - 0.133 radians/s

So, -0.133 radians/s is the angle between the ladder and the ground changing when the bottom of the ladder is 8 ft from the wall.

3 0

3 years ago