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Post New Question
All Questions
+0
230858 Questions
-2
249
0
+54
calc
What is the radius in nm of the electron orbit of a hydrogen atom for n = 2?
Evanumber001
Dec 8, 2021
-2
259
0
+54
calc
What is the radius in nm of the electron orbit of a hydrogen atom for n = 1?
Evanumber001
Dec 8, 2021
-1
286
0
+54
calc
Photons of a certain infrared light have an energy of 1.12 10-19 J.
(a) What is the frequency of this IR light?
read more ..
Evanumber001
Dec 8, 2021
-1
270
0
+54
calc
Photons of a certain ultraviolet light have an energy of 6.68 10-19 J.
(a) What is the frequency of this UV light?
read more ..
Evanumber001
Dec 8, 2021
0
232
2
Number Theory
How many positive perfect cube factors does 3*6*5*10*12 have?
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Guest
Dec 8, 2021
0
185
0
Algebra
Find the product of all positive integer values of c such that 8x^2 + 158x + c = 0 has two real roots.
Guest
Dec 8, 2021
0
311
1
help geometry
A sector of a circle has a central angle of 80 degrees. If the area of the sector is 35pi, what is the radius of the circle?
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Guest
Dec 8, 2021
0
296
1
+129
Math
In an online media store, downloaded songs cost $3d each and books cost $9b each. Caleb purchased 15 songs and 3 books this month, and also paid $7 in sales tax. Write and simplify an expression to show how much Caleb spent on everything including tax.
possible
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Soyoxxommm
Dec 8, 2021
0
323
2
Geometry
Triangles BDC and ACD are coplanar and isosceles. If we have angle ABC = 72 degrees, what is angle BAC, in degrees?
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Guest
Dec 8, 2021
0
380
1
+101
can anyone help with this? I tried with starting a diagram but I still dont get it
A construction worker stands at a point due west of a building and finds the angle of elevation to the top of the newly constructed part is 35˚. Another construction worker stands due east of the same building and finds the angle of elevation to be 50˚
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vxnessa
Dec 8, 2021
0
188
0
geometry
A pyramid with volume 40 cubic inches has a rectangular base. If the length of the base is doubled, the width tripled and the height increased by 60%, what is the volume of the new pyramid, in cubic inches?
Guest
Dec 8, 2021
0
230
1
Geometry
In the diagram, four circles of radius 1 with centres P, Q, R, and S are tangent to one another and to the sides of triangle ABC, as shown. What is the area of triangle ABC?
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Guest
Dec 8, 2021
Dec 7, 2021
0
308
0
+633
Calculating Permutations to a Sum with Limited Conditions
Hello, sorry if this comes out looking weird, but side note, I'm only able to make questions in the source code editor atm :P
Anyways I was thinking about a problem recently that I remembered had a pretty cool solution, but I can't remember
read more ..
helperid1839321
Dec 7, 2021
0
162
0
Quadratic
If x^2 - 77x + c = (x + a)^2 for some constants c and a, find a.
Guest
Dec 7, 2021
0
207
1
Quadratic
For what real values of a is x^2 + ax + 625 the square of a binomial? If you find more than one, then list the values separated by commas.
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Guest
Dec 7, 2021
0
352
3
Probability
Two numbers, x and y are selected at random from the interval (0, 3). What is the probability that a triangle with sides of length 2, x, and y exists?
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Guest
Dec 7, 2021
-1
305
1
+218
An arithmetic progression has a common decrement of 7. What do we know about it's nth term? What don't we know?
An arithmetic sequence decreases by 7. What do you know about it's nth term? What don't you know?
Pleas help me.
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MathyGoo13
Dec 7, 2021
0
181
0
Probability
Lizzie rolls two dice. What is the probability that one of the dice shows a $5$ or the total sum of both dice is a prime number (or both)?
Guest
Dec 7, 2021
0
309
1
Probability
Mike draws six cards from a standard 52-card deck. What is the probability that he draws a card from at least three of the four suits? Express your answer as a simplified fraction.
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Guest
Dec 7, 2021
0
277
2
How can you get to 64 by using all of these numbers 1 time
How can you get to 64 by using all of these numbers 1 time
7,7,7, +, division, ( )
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Guest
Dec 7, 2021
0
281
1
plz help asap than u
produce a recipe table to show how you would make a dilution series from 1M sodium chloride solution giving 10cm^3 of each dilution.
Produce a recipe table to show how you would make a series dilution of a plant mineral solution to
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Guest
Dec 7, 2021
0
277
1
help with inequality
Find all the values of x such that (4x - 5)/(3x + 5) >= 3 + 1/(3x + 5).
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Guest
Dec 7, 2021
0
378
4
Find all real values of x for which
Find all real values of x for which
sqrt (4x^2 + 12x + 9) = 2x+ 3
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Guest
Dec 7, 2021
0
164
0
Counting problem
The product of all digits of positive integer M is 105. How many such Ms are there with four digits?
Guest
Dec 7, 2021
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