On a coordinate plane, a circle has a center at (8, 9). Concentric circles are circles with the same center but different radii. Which equations represent concentric circles along with the circle shown in the graph? Check all that apply. x2 + y2 = 25 (x – 8)² + (y – 9)² = 3 (x – 8)² + (y – 9)² = 14 (x – 8)² + (y + 9)² = 3 (x + 8)² + (y + 9)² = 25 (x + 9)² + (y + 8)² = 3

Step-by-step explanation:

The equation of a circle with center (h, k) and radius r is ...

  (x -h)² +(y -k)² = r²

Circles concentric with one having its center at (8, 9) will have equations of the form ...

  (x -8)² +(y -9)² = r²

The offered answer choices that have this form are ...

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.