Answer:
Let R be the greater radius and r be the smaller radius
A) Area of the sidewalk = R^2 - r^2 - This can be the expression
B) = 3.14
=(R^2-r^2)
=(11^2-9^2)
=(121-81)
=*40
That was the simplified expression
Answer = 3.14 * 40 = 125.6m^2
Step-by-step explanation:
Answer: 
<u>Step-by-step explanation:</u>
![\text{Use the distance formula: }d_AB=\sqrt{(x_A-x_B)^2+(y_A-y_B)^2}\\where\ (X_A, y_A)=(-3, -2)\\and\ (x_B,y_B)=(4, -7)\\\\\\d_AB=\sqrt{(-3-4)^2+[-2-(-7)]^2}\\\\.\quad =\sqrt{(-7)^2+(5)^2}\\\\.\quad =\sqrt{49+25}\\\\.\quad =\boxed{\sqrt{74}}](https://tex.z-dn.net/?f=%5Ctext%7BUse%20the%20distance%20formula%3A%20%7Dd_AB%3D%5Csqrt%7B%28x_A-x_B%29%5E2%2B%28y_A-y_B%29%5E2%7D%5C%5Cwhere%5C%20%28X_A%2C%20y_A%29%3D%28-3%2C%20-2%29%5C%5Cand%5C%20%28x_B%2Cy_B%29%3D%284%2C%20-7%29%5C%5C%5C%5C%5C%5Cd_AB%3D%5Csqrt%7B%28-3-4%29%5E2%2B%5B-2-%28-7%29%5D%5E2%7D%5C%5C%5C%5C.%5Cquad%20%3D%5Csqrt%7B%28-7%29%5E2%2B%285%29%5E2%7D%5C%5C%5C%5C.%5Cquad%20%3D%5Csqrt%7B49%2B25%7D%5C%5C%5C%5C.%5Cquad%20%3D%5Cboxed%7B%5Csqrt%7B74%7D%7D)
Answer:
10 hr
Step-by-step explanation:
i divided 990 by 90 and got 10 hr
Since it is a slope, the equation of a slope is y=Mx+b. So you want to get b to that format. To do this, you need to isolate the y on the left. To do this, you simply add 2x to both sides. Your final answer will be y=2x+7. Hope this helps!
