CPhill

The molar mass of arsenic =  74.92160 g/mol

To calculate moles, we have

grams of substance / moles of substance =  74.92160 g/mol 

3.65x10^-3 g  / moles of substance =   74.92160 g/mol 

moles of substance = 3.65x10^-3 g/  74.92160 g/mo =

0.0000487175927903 moles =

about  4.87 x 10^(-5) moles

(2 cos θ)^2  =

4 cos^2 θ =

4 (1 - sin^2 θ ) =

4 ( 1 + sin θ) (1 - sin θ)  

Other forms are also possible........ !!!

(((1.45-1)*(100/1.45))-((100-(100/1.45))))/(1.45-1)  simplify

[(.45)*(100/1.45) - 100 + (100/1.45)] / .45 =

[(45/1.45) - 100 + (100/1.45)] / .45 =  

[multiply the top and bottom of both fractions in the numerator by 20]

[900/29 -  100 + 2000/29] / .45 =

[ 2900/29 - 100] / .45  =

[100 - 100] / .45 =

0 / .45 = 

0

And there you go....

BTW......this isn't an "equation"..it's just an "expression"....

Well....we couldn't POSSIBLY be wrong about a "counting" problem.....could we???

LOL !!!!!!

Thanks......!!!

2 minutes  = 120 seconds   ...  so ....

48.5 / 120  =   485 / 1200 = about 40.4%

Yeah...I got the same answer, Melody.....I believe this is correct because one box looks like another....and all the b***s look the same.....

6x^2 + 8x - 128 = 0    divide everything by 2

3x^2 + 4x - 64 = 0       factor...  and set each factor to 0

(3x + 16) (x - 4) = 0

One solution is x = 4

The other is x = -16/3

(8b^(2/3)*9t^(1/5)) (8b^(5/3)*9t^(3/5)) ......  rearrange.......

[8b^(2/3) * 8b^(5/3)] * [ 9t^(1/5) * 9t^(3/5) ] =

[64 b^(7/3)] * [ 81 t^(4/5) ] =

5184* b^(7/3)* t^(4/5)

And that's it.....!!!!