Square root -80 by using imaginary unit I

What is the approximate circumference of the circle shown below?

2x + 1 < 5 solve the following inequality. then place the correct number in the box provided.

The level of co2 emissions, f(x), in metric tons, from the town of fairfax x years after they started recording is shown in the table below. x 2 4 6 8 10 f(x) 26,460 29,172.15 32,162.29 35,458.93 39,093.47 select the true statement.