Question

One hamburger and one coke cost $3.20. Three hamburgers and one coke cost $8.00. Find the cost of one hamburger.

$2.40
$2.60
$4.80
$0.80
$2.10

Answer 1

$0.80

Explanation:

-3 (1x + 1y = 3.2)

3x + 1y = 8

----------------

-3x - 3y = -9.6

+

3x + 1 y = 8

-------------------

0x -2y = -1.6

÷ -2

-----------------

y = 0.8

one hamburger costs $0.80