If all 25 questions are different,
When order of selection counts:
P(25,7)
=25!/(25-7)!
=15511210043330985984000000/6402373705728000
=2422728000
When order of selection does not count count:
C(25,7)
=25!/(7!*(25-7)!)
=15511210043330985984000000/(6402373705728000*5040)
=480700
Answer:
(x-1)^2+(y+1)^2=3
Step-by-step explanation:
x² + y2 - 2x + 2y - 1 = 0
add the 1 to get it to the other side of the equation
x² + y2 - 2x + 2y = +1
group the x's and y's
(x² -2x) + (y2+2y) = +1
then you'll complete the square on the -2x and + 2y. that just means divide by two and then raise it to the 2nd power.
so (-2/2)^2 and (+2/2)^2
(x²-2x+1)+(y2+2y+1) = 1+1+1
you add the one's to the other side because whatever is done to one side must be done to the other
you'll then need to factor again.
(x-1)^2+(y+1)^2=3
to factor it take one of your squared x's, the sign of the middle term within the parentheses , then the square root of the last term within the parentheses. remeber to put your ^2 (raised to the 2nd power) outside of the parentheses when you finish.
If a = 10, then the equation would be 10+6.
The answer would be 16.
Hope this helps! :D
The first one would be $160 and the second one would be $525
