Answer:
See Explanation
Step-by-step explanation:
![log(x + y) = log3 + \frac{1}{2} logx+ \frac{1}{2} logy \\ \\ log(x + y) = log3 + logx ^{\frac{1}{2}} + logy ^{\frac{1}{2}}\\ \\ log(x + y) = log3 + log(xy) ^{\frac{1}{2}} \\ \\ log(x + y) = log[3(xy) ^{\frac{1}{2}}] \\ \\ x + y = 3(xy) ^{\frac{1}{2}} \\ \\ squaring \: both \: sides \\ {(x + y)}^{2} = \bigg(3(xy) ^{\frac{1}{2}} \bigg)^{2} \\ \\ {x}^{2} + {y}^{2} + 2xy = 9xy \\ \\ {x}^{2} + {y}^{2} = 9xy - 2xy \\ \\ \purple{ \bold{{x}^{2} + {y}^{2} = 7xy}} \\ thus \: proved](https://tex.z-dn.net/?f=log%28x%20%2B%20y%29%20%3D%20log3%20%2B%20%20%5Cfrac%7B1%7D%7B2%7D%20logx%2B%20%20%5Cfrac%7B1%7D%7B2%7D%20logy%20%5C%5C%20%20%5C%5C%20log%28x%20%2B%20y%29%20%3D%20log3%20%2B%20%20%20%20logx%20%5E%7B%5Cfrac%7B1%7D%7B2%7D%7D%20%2B%20%20%20logy%20%5E%7B%5Cfrac%7B1%7D%7B2%7D%7D%5C%5C%20%20%5C%5C%20%20log%28x%20%2B%20y%29%20%3D%20log3%20%2B%20%20%20%20log%28xy%29%20%5E%7B%5Cfrac%7B1%7D%7B2%7D%7D%20%5C%5C%20%20%5C%5C%20log%28x%20%2B%20y%29%20%3D%20%20log%5B3%28xy%29%20%5E%7B%5Cfrac%7B1%7D%7B2%7D%7D%5D%20%5C%5C%20%20%5C%5C%20x%20%2B%20y%20%3D%203%28xy%29%20%5E%7B%5Cfrac%7B1%7D%7B2%7D%7D%20%5C%5C%20%20%5C%5C%20squaring%20%5C%3A%20both%20%5C%3A%20sides%20%5C%5C%20%20%7B%28x%20%2B%20y%29%7D%5E%7B2%7D%20%20%3D%20%20%5Cbigg%283%28xy%29%20%5E%7B%5Cfrac%7B1%7D%7B2%7D%7D%20%5Cbigg%29%5E%7B2%7D%20%20%5C%5C%20%20%5C%5C%20%20%7Bx%7D%5E%7B2%7D%20%20%2B%20%20%7By%7D%5E%7B2%7D%20%20%2B%202xy%20%3D%209xy%20%5C%5C%20%20%5C%5C%20%20%7Bx%7D%5E%7B2%7D%20%20%2B%20%20%7By%7D%5E%7B2%7D%20%20%3D%209xy%20-%202xy%20%5C%5C%20%20%5C%5C%20%20%20%5Cpurple%7B%20%5Cbold%7B%7Bx%7D%5E%7B2%7D%20%20%2B%20%20%7By%7D%5E%7B2%7D%20%20%3D%207xy%7D%7D%20%5C%5C%20thus%20%5C%3A%20proved)
Answer:
79
Step-by-step explanation:
The area of a circle is pi*radius^2; the radius of this circle is 10 (20/2=10). Our area is then 100pi or ~314 square feet. A 2x2 square takes up 4 feet. 314/4 is equal to 78.5, or when rounded, 79
Answer:
Bruno is correct. When going from a larger unit to a smaller unit you need to divide
Step-by-step explanation:
Sam's calculation:
45.7 + 40.9 + 38.0 = 124.6 miles. 124.6 × 0.621 = 77.38 kilometers.
Bruno's calculation:
45.7 + 40.9 + 38.0 = 124.6 miles. 124.6 divided by 0.621 = 200.64 kilometers.
1 kilometer = 0.621 miles.
Bruno is correct. When going from a larger unit to a smaller unit you need to divide
We will divide a larger value by a smaller value to get the smaller units
A + b - c = 180
a + b - c (+c) = 180 (+c)
a + b (-b) = 180 + c (-b)
a = 180 + c - b
hope this helps
