Start by writing the system down, I will use
to represent 

Substitute the fact that
into the first equation to get,

Simplify into a quadratic form (
),

Now you can use Vieta's rule which states that any quadratic equation can be written in the following form,

which then must factor into

And the solutions will be
.
Clearly for small coefficients like ours
, this is very easy to figure out. To get 5 and 6 we simply say that
.
This fits the definition as
and
.
So as mentioned, solutions will equal to
but these are just x-values in the solution pairs of a form
.
To get y-values we must substitute 3 for x in the original equation and then also 2 for x in the original equation. Luckily we already know that substituting either of the two numbers yields a zero.
So the solution pairs are
and
.
Hope this helps :)
Answer:
an = 63(-1/3)^(n-1)
Step-by-step explanation:
This is a geometric sequence with first term 63 and common ratio -1/3.
The equation for the nth term is
an = 63(-1/3)^(n-1).
<span>Provided that no one can receive more than one prize, there are 50*49*48= 117600 ways to distribute the prizes. The first prize can be given to any of the 50 people, the second to any of the remaining 49, and the third to the remaining of the 48, multiplying these possibilities together leads to the answer.</span>