i dont know if im right......
2. x = 9
3. x = -7
4. x = 3.42 or 3.41
Y = 2.5x - 500
I simplified it a bit, you could write it as y = 5x - 2.5x - 500
Trevor invested $ 4720
<em><u>Solution:</u></em>
Given that, Trevor earned $ 826 on account during 2.5% annual interest for seven years
We can simple interest formula
<em><u>The formula for simple interest is given as:</u></em>

Where,
"p" is the principal
"n" is the number of years
"r" is the rate of interest
Here given that,
Principal = p = ?
rate of interest = r = 2.5 %
number of years = n = 7
Simple interest earned = 826
<em><u>Substituting the values in above formula,</u></em>

Thus he invested $ 4720
Answer:$7,200
Quantities that changed in the problem are
1. The value of the coin
2. The time it took to appreciate to that value
Step-by-step explanation:
Current value = $5,400
Increase in value (monthly) = $30
In 5 years time, the value would increase by
(12*5) * $30 = $1800
Value in five years = current value + increase in value
Value in five years = $5400 + $1800
Value in five years = $7,200