X-9=8(2x+3)-18
x-9=16x+24-18
-9=15x+6
-15=15x
x=-1
So 15 gallons of gas brought it from 1/8 full to 3/4 full.
Let's change 3/4 to the equivalent fraction 6/8 so that the denominators are the same. (3/4 = 6/8)
So 15 gallons of gas brought it from 1/8 to 6/8 Those 15 gallons must be 5/8 of the tank's capacity 6/8 - 1/8 = 5/8
So 15 is 5/8 of what number? (This will tell us the capacity of the whole tank)
15 = 5/8n
Divide both sides by 5/8 (remembering to multiply by the reciprocal 8/5)
15 ÷ 5/8 = 15 x 8/5 = 18
So the tank holds 24 gallons and (since it is 3/4 full or has 18 gallons) it needs 6 gallons to fill the tank.
Check - at first 1/8 full (1/8 of 24 = 3) So we started with 3 gallons. 15 gallons added to the 3 gallons is 18 gallons. Now the tank is 6/8 (3/4 full). The remaining 1/4 (2/8) of a tank is the difference between 18 and it's capacity (24 gallons) so it will need 6 gallons to fill it up..
Use a variable to represent the number of hours the technician will work, plus the $50.
50+25x
This would be the expression used to find the amount of money the technician needs.
Answer:
The answer is Tonya's phone had the greater initial trade-in value.
Leo's phone decreases at an average rate slower than the trade in value of Tonya's phone.
Step-by-step explanation:
Given
Tonya

Leo




Solving (a): The phone with greater initial value
The initial value is when x = 0. So, we have:




From Leo's table

By comparison;

i.e.

<em>So: Tonya's had the greater initial trade-in value</em>
Solving (b): The phone with lesser rate
An exponential function is:

Where:

For Tonya

For Leo, we have:


So, the equation becomes:

and 
Solving
, we have:



becomes

Divide both sides by 480

Take square roots

-- Leo's rate
By comparison; Leo's rate is slower i.e. 0.87 < 0.88
12x = 12; x = 1
That simple