Answer
x = 1
Explanation:
Given the following equation
![\begin{gathered} (2x+2)^{\frac{1}{2}}=\text{ -2} \\ \text{According to the law of indicies} \\ x^{\frac{1}{2}}\text{ = }\sqrt[]{x} \\ (2x+2)^{\frac{1}{2}}\text{ = }\sqrt[]{(2x\text{ + 2)}} \\ \text{Step 1: Take the square of both sides} \\ \sqrt[]{(2x\text{ + 2) }}\text{ = -2} \\ \sqrt[]{(2x+2)^2}=-2^2 \\ 2x\text{ + 2 = 4} \\ \text{Collect the like terms} \\ 2x\text{ = 4 - 2} \\ 2x\text{ = 2} \\ \text{Divide both sides by 2} \\ \frac{2x}{2}\text{ = }\frac{2}{2} \\ x\text{ = 1} \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20%282x%2B2%29%5E%7B%5Cfrac%7B1%7D%7B2%7D%7D%3D%5Ctext%7B%20-2%7D%20%5C%5C%20%5Ctext%7BAccording%20to%20the%20law%20of%20indicies%7D%20%5C%5C%20x%5E%7B%5Cfrac%7B1%7D%7B2%7D%7D%5Ctext%7B%20%3D%20%7D%5Csqrt%5B%5D%7Bx%7D%20%5C%5C%20%282x%2B2%29%5E%7B%5Cfrac%7B1%7D%7B2%7D%7D%5Ctext%7B%20%3D%20%7D%5Csqrt%5B%5D%7B%282x%5Ctext%7B%20%2B%202%29%7D%7D%20%5C%5C%20%5Ctext%7BStep%201%3A%20Take%20the%20square%20of%20both%20sides%7D%20%5C%5C%20%5Csqrt%5B%5D%7B%282x%5Ctext%7B%20%2B%202%29%20%7D%7D%5Ctext%7B%20%3D%20-2%7D%20%5C%5C%20%5Csqrt%5B%5D%7B%282x%2B2%29%5E2%7D%3D-2%5E2%20%5C%5C%202x%5Ctext%7B%20%2B%202%20%3D%204%7D%20%5C%5C%20%5Ctext%7BCollect%20the%20like%20terms%7D%20%5C%5C%202x%5Ctext%7B%20%3D%204%20-%202%7D%20%5C%5C%202x%5Ctext%7B%20%3D%202%7D%20%5C%5C%20%5Ctext%7BDivide%20both%20sides%20by%202%7D%20%5C%5C%20%5Cfrac%7B2x%7D%7B2%7D%5Ctext%7B%20%3D%20%7D%5Cfrac%7B2%7D%7B2%7D%20%5C%5C%20x%5Ctext%7B%20%3D%201%7D%20%5Cend%7Bgathered%7D)
Therefore, x = 1
Let x represent the number of half-gallons purchased by the store. Then x-13 is the number sold, and 2.80x is the store's cost. The revenue is 4.06(x-13) and the difference between that and cost is the profit.
... 4.06(x -13) -2.80x = 63.14
... 1.26x - 52.78 = 63.14 . . . . eliminate parentheses, collect terms
... 1.26x = 115.92 . . . . . . . . . . add 52.78
... x = 115.92/1.26 = 92 . . . . . divide by the coefficient of x
The store purchased 92 half-gallons of milk.
