Answer:
Step-by-step explanation:
Let's calculate the answer to the second parenthesis. Just multiply throughout to get -8xyz. Then, multiply the first parenthesis by the second. Multiply the constants (-8 and 2) first to get -16, multiply the x's together to get x^2, the y's together to get y^2, and the z's together to get z^2. Put it all together to get .
Answer: 879.20 km²
<u>Step-by-step explanation:</u>
The diameter of the big circle is 2(10) + 18 = 38
divide the diameter by 2 to get the radius (r) = 19
Area (A) = π·r²
= π(19)²
= 361π
The diameter of the small circle is 18
divide the diameter by 2 to get the radius (r) = 9
Area (A) = π·r²
= π(9)²
= 81π
The area of the shaded region is the difference between the big circle and the small circle.
= 361π - 81π
= 280π
= 280(3.14)
= 879.20
