Question

The yearly cost y for driving a certain car is $7,800 for 10,000 miles

Answer 1

Answer:

y = 0.36x + 4200.00

15100.00 miles.

Step-by-step explanation:

If the yearly cost for driving x miles is given by y dollars then the two ordered pairs to find the linear relation between x and y are (10000,7800) and (20000,11400).

So, the equation will be

$\frac{y - 11400}{11400 - 7800} = \frac{x - 20000}{20000 - 10000}$

⇒ $\frac{y - 11400}{3600} = \frac{x - 20000}{10000}$

⇒ $y - 11400 = \frac{9}{25}(x - 20000)$

⇒ $y - 11400 = \frac{9}{25}x - 7200$

⇒ $y = \frac{9}{25}x + 4200$

⇒ y = 0.36x + 4200.00 ........... (1) (Answer)

Now, for y = $9636.00, from equation (1),

9636 = 0.36x + 4200

⇒ 0.36x = 5436

⇒ x = 15100.00 miles. (Answer)