3x + 4y = 16
<u>- 3x -3x</u>
4y = -3x + 16 (divide each side by 4)

y = -3/4x + 16/4
The answer is
1) week 2 she spent $29.21
You would multiply the gallons of gas she bought by the price of each gallon.
2) $1.06 more because you would subtract week 1’s by week 4’s total
2/8, 3/12, 4/16, 5/20, 6/24, 7/28, 8/32, 9/36, 10/40, 11/44, 12/48, etc.