All categories

3 years ago

16. What is the value of the expression (x + 5)(2y - 1) when x = 1 and y=-1?

Mathematics

1 answer:

nirvana33 [79]3 years ago

5 0

Answer:

Step-by-step explanation:

If you sub in all the values, you get [1+5][2(-1)-1]. Now combine like terms. 1+5 is 6 and 2*-1-1=-3. 6*-3=-18 so the answer is A.

You might be interested in

All of the following are terminating decimals except _____. 1/8 2/5 2/3 17/50

klemol [59]

2/3 is the answer Hope this helps. :)

5 0

3 years ago

Read 2 more answers

Water is added to a cylindrical tank of radius 5 m and height of 10 m at a rate of 100 L/min. Find the rate of change of the wat

nirvana33 [79]

Answer:

$V = \pi r^2 h$

For this case we know that $r=5m$ represent the radius, $h = 10m$ the height and the rate given is:

$\frac{dV}{dt}= \frac{100 L}{min}$

$Q = 100 \frac{L}{min} *\frac{1m^3}{1000L}= 0.1 \frac{m^3}{min}$

And replacing we got:

$\frac{dh}{dt}=\frac{0.1 m^3/min}{\pi (5m)^2}= 0.0012732 \frac{m}{min}$

And that represent $0.127 \frac{cm}{min}$

Step-by-step explanation:

For a tank similar to a cylinder the volume is given by:

$V = \pi r^2 h$

For this case we know that $r=5m$ represent the radius, $h = 10m$ the height and the rate given is:

$\frac{dV}{dt}= \frac{100 L}{min}$

For this case we want to find the rate of change of the water level when h =6m so then we can derivate the formula for the volume and we got:

$\frac{dV}{dt}= \pi r^2 \frac{dh}{dt}$

And solving for $\frac{dh}{dt}$ we got:

$\frac{dh}{dt}= \frac{\frac{dV}{dt}}{\pi r^2}$

We need to convert the rate given into m^3/min and we got:

$Q = 100 \frac{L}{min} *\frac{1m^3}{1000L}= 0.1 \frac{m^3}{min}$

And replacing we got:

$\frac{dh}{dt}=\frac{0.1 m^3/min}{\pi (5m)^2}= 0.0012732 \frac{m}{min}$

And that represent $0.127 \frac{cm}{min}$

5 0

3 years ago

Sooooooooo technically i've neevr lost a fight with a tiger

Aloiza [94]

Answer:

oh thats cool

Step-by-step explanation:

3 0

3 years ago

An engineer is designing a storage compartment in a spacecraft .The compartment must be 2 meters longer than it is wide, and its

serg [7]

Answer:

Let x be the width of the compartment,

Then according to the question,

The length of the compartment = x + 2

And the depth of the compartment = x -1

Thus, the volume of the compartment, $V = (x+2)x(x-1) = x^3 + x^2 - 2x$

But, the volume of the compartment must be 8 cubic meters.

⇒ $x^3 + x^2 - 2x = 8$

⇒ $x^3 + x^2 - 2x - 8=0$

⇒ $(x-2)(x^2+3x+4)=0$

If $x-2=0\implies x = 2$ and if $x^2+3x+4=0\implies x = \text{complex number}$

But, width can not be the complex number.

Therefore, width of the compartment = 2 meter.

Length of the compartment = 2 + 2 = 4 meter.

And, Depth of the compartment = 2 - 1 = 1 meter.

Since, the function that shows the volume of the compartment is,

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

When we lot the graph of that function we found,

V(x) is maximum for infinite.

But width can not infinite,

Therefore, the maximum value of V(x) will be 8.

8 0

3 years ago

Read 2 more answers

A kite flying in the air has a 12 line attached to it. Its line is pulled taut and casts a 9 shadow. Find the height of the kite

alexira [117]

Answer:

8 (7.94)

Step-by-step explanation:

You can think of it as a geometry problem.

What is formed here is a triangle, which sides ate: the line, the line's shadow, and the height from the ground to the kite (here I attach a drawing).

What you need to find is the height. We will call it H.

As the triangle formed is a right one, we can use Pitágoras' theorem. The height H squared plus the squared of the shadow is equal to the squared of the line (the hypotenuse). This is:

H^2 + 9^2 = 12^2

H^2 + 81= 144

H^2 = 63

Applying squared root in both sides

H = √63

H = 7,94

So, the height is approximately 8.

4 0

3 years ago