Someone please help me with equation :)

Use the formula pi r^2. You are finding the radius. Plug the numbers in.

Should be the second one.

First you have to think that the entire circle is blue. So the area of the blue circle is: 3.14*11^2 = 379.94.

Then you have to look at the smaller circle. There the radius is: 3. So the area would be: 3.14*3^2 = 28.26

They are asking you to find the shaded area. So you subtract the bigger circles area with the smaller circle.

379.94 - 28.26 = 351.68 to the exact.

300pi

step-by-step explanation:

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places