Answer:
They purchased 6 dozen eggs
Step-by-step explanation:
The total cost is the cost per dozen times the number of dozen purchased
total cost = 1.98 * n where n is the number of dozen
11.88 = 1.98n
Divide each side by 1.98
11.88/1.98 = 1.98/1.98 * n
6=n
They purchased 6 dozen eggs
The easy thing to do is eliminate x by subtraction
x + 7y = 24
- x - 9y = -24
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16y = 48
now solve for y and then substitute the value into either original equation to find x
Use substitution
Given both y values, you know that they have to be equal
3x + 3 = x - 1
2x + 3 = -1
2x = -4, divide by 2
x = -2
Now plug x value into any of the equation to find y value
y = 3(-2) + 3
y = -6 + 3, y = -3
Solution: x = -2, y = -3
