All categories

3 years ago

If 4x +5=9x-2,then x=

Mathematics

1 answer:

user100 [1]3 years ago

5 0

You might be interested in

What equation best represents the following sentence?

nikdorinn [45]

Answer: n + 2 = 2n

Step-by-step explanation:

sum = add

number and two = n, 2

twice the number = 2 x n

4 0

2 years ago

The surface area of a melting snowball decreases at a rate of3.8cm2/min. Find the rate at which its diameter decreases when the

Scorpion4ik [409]

Answer:

Step-by-step explanation:

This is a pretty basic related rates problem. I'm going to go through this just like I do in class when I'm teaching it to my students.

We see we have a snowball, which is a sphere. We are talking about the surface area of this sphere which has a formula of

$S=4\pi r^2$

In the problem we are given diameter, not radius. What we know about the relationship between a radius and a diameter is that

d = 2r so

$\frac{d}{2}=r$ Now we can have the equation in terms of diameter instead of radius. Rewriting:

$S=4\pi(\frac{d}{2})^2$ which simplifies to

$S=4\pi(\frac{d^2}{4})$ and a bit more to

$S=\pi d^2$ (the 4's cancel out by division). Now that is a simple equation for which we have to find the derivative with respect to time.

$\frac{dS}{dt}=\pi*2d\frac{dD}{dt}$ Now let's look at the problem and see what we are given as far as information.

The rate at which the surface area changes is -3.8, and we are looking for $\frac{dD}{dt}$ , the rate at which the diameter is changing, when the diameter is 13. Filling in:

$-3.8=\pi(2)(13)\frac{dD}{dt}$ and solving for the rate at which the diameter is changing:

$-\frac{3.8}{26\pi}=\frac{dD}{dt}$ and divide to get

$\frac{dD}{dt}=-.459\frac{cm}{min}$ Obviously, the negative means that the diameter is decreasing.

7 0

3 years ago

Roland had $10,500 in medical expenses last year and has no medical insurance. The IRS allows medical expense deductions for the

Sloan [31]

$8,175
you may have to work it out if the numbers are different but this should be the correct answer

8 0

3 years ago

Answer and explain please ILL MARK BRAINLIEST PLEASE HELP

Slav-nsk [51]

Answer:

8:30 am

Step-by-step explanation:

8 0

3 years ago

The price of a pie is now $11. how many pies are sold? how many pies does each producer make? how many producers are there? how

Anettt [7]

Is there suppose to be a link or something more to this question?

3 0

2 years ago