Answer:
And the probability that the first die shows an odd number is 1/2, as is the probability that the second does. Since the dice fall independently, P(both are odd) = P(first is odd)*P(second is odd) = (1/2)*(1/2) = 1/4. Therefore P(at least one is even) = 1 - 1/4 = 3/4.

Step-by-step explanation:
So we go backwards, since we have x= 1/2 , 7

Now we have to foil to get the quadratic

We must simplify the terms

Our final result comes out to be

Let's say hmm let's use the figures in thousands, so
model A costs 90 + 4 per year, so... ok.. after "t" years, then the cost for model A is then 90 + 4*t, or
A = 90 + 4t.
now, model B is 70 + 10 per year, so,... after "t" years, model B is then
B = 70 + 10 * t, or
B = 70 + 10t.
if we were to assume A < B, namely the cost of A is less than B, what would the years be? namely, what's "t"?

after that period, then A becomes cheaper than B.
The answer for number one is -3.938.
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