We will get the number of possible selections, and then subtract the number less than 25 cents.
We can choose the number of dimes 5 ways 0,1,2,3 or 4.
We can choose the number of nickels 4 ways 0,1,2 or 3.
We can choose the number of quarters 3 ways 0,1, or 2.
That's 5*4*3 = 60 selections
Now we must subtract from the 60 the number of selections of coins that are less than 25 cents. These will involve only dimes and nickels.
To get a selection of coin worth less than 25 cents:
If we use no dimes, we can use 0,1,2 on all 3 nickels.
That's 4 selections less than 25 cents. (that includes the choice of No coins at all in the 60, which we must subtract).
If we use exactly 1 dime , we can use 0,1,2, or all 3 nickels.
That's the 3 combinations less than 25 cents.
And there is 1 other selection less than 25 cents, 2 dimes and no nickels.
So that's 4+3+1 = 8 selections which we must subtract from the 60.
Answer 60-8 = 52 selections of coins worth 25 cents or more.
After you type in your equations and hit graph you notice that, if you are in the standard window, your parabola is cut off so you have to choose your "window" button to change the viewing window to see the whole graph. Then you would use your 2nd button and "trace" and "intersect" to find the points of intersection of the 2 graphs. The first point is at (-.90901, 16.81812) and the second point is at (5.9090909, 3.1818182). Graphing calculators are quite amazing!
Cos (x+y)/cos x sin y
= cos x cos y - sin x sin y / cos x sin y
= cos x cos y/cos x sin y - sin x sin y / cos x sin y
hope this helps
y=2x so replacr the -y with -2x so 2x+6 is 8x. :)
It would be 0.125 because by converting percent to a decimal you must first multiply 0.0025 x 50.
Hope that helps
