Answer:
12 = -3 - 3x
Step-by-step explanation:
Same concept as the last question I answered. First, let's derive a formula from the given model. So we have 3 negative x and 3 negative 1 which equal to 12 positive ones, this can be written as:
-3x - 3 = 12
which can be rewritten as
12 = -3 - 3x
Answer:
no
Step-by-step explanation:
if he randomly pulls it out it's still the same number of red cards and also the total number of cards as always
can't change
Multiplying the number by 1,000
Let's start from what we know.

Note that:

(sign of last term will be + when n is even and - when n is odd).
Sum is finite so we can split it into two sums, first

with only positive trems (squares of even numbers) and second

with negative (squares of odd numbers). So:

And now the proof.
1) n is even.
In this case, both

and

have

terms. For example if n=8 then:

Generally, there will be:

Now, calculate our sum:



So in this case we prove, that:

2) n is odd.
Here,

has more terms than

. For example if n=7 then:

So there is

terms in

,

terms in

and:

Now, we can calculate our sum:




We consider all possible n so we prove that:
Answer:
6x^2 -11x -1
Step-by-step explanation:
(3x^2 + 3) - (6x + 4) + (3x^2 - 5x)
Distribute the minus sign
(3x^2 + 3) - 6x - 4) + (3x^2 - 5x)
Combine like terms
3x^2 + 3x^2 - 6x - 5x -4+3
6x^2 -11x -1