I hope this helps you
(fog)(5)=f (g (5))=?
x= 5 g (5)=-4.5+3=-20+3=-17
f (g(5))=f (-17)=-2. (-17)-7
f (-17)=34-7
f (-17)=27
For the equation:
-1=5 x^2 - 2 x
5 x^2 - 2 x + 1 = 0, then we substitute: a=5, b=-2, c =1
to discriminant formula: D= b^2 - 4 a c = (-2)^2 - 4 * 5 * 1 = 4 - 20 = - 16
Answer:
The discriminant is equal to -16 which means the equation has no real number solutions.
25 a² + 20 ab + 4 b²
for formula

find u,v such that: u.v = a
and u+v = b then group according to

=

factor out 5a from :

factor out 2b from :

=

factor out :

=

Refine:

hope this helps!.
Answer:
2730
Step-by-step explanation:
We want to determine the greatest common divisor of the elements of the set 
We apply the Fermat's little theorem which states that if p is a prime number, then for any integer a, the number aᵖ − a is an integer multiple of p.
Now,
if p-1 divides 12.
Since the of 12 are 1,2,3,4, 6, 12, the corresponding primes are 2, 3, 5, 7, 13.
Therefore, the gcd of the elements in
and 
2*3*5*7*13=2730
Therefore, the gcd of the elements in set S is 2730.