Question

Which equation describes the circle

with center (5,-1) and radius 7?
A (x - 5)' + (y +1)* = 7
B (x - 5)* + (y + 1)* = 49
(x + 5) * + (y - 1) = 7
D(x + 5)' + (y - 1)' = 49

Answer 1

B. (x-5)²+(y+1)² = 49

Explanation:

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

`\large \boxed{ {(x - h)}^(2) + {(y - k)}^(2) = {r}^(2) }`

We have all given information we need. Our h is 5 - Our k is -1 and our radius is 7

Substitute these values in

`\large{ {(x - 5)}^(2) + {(y - ( - 1))}^(2) = {7}^(2) } \\ \large{ {(x - 5)}^(2) + {(y + 1)}^(2) = {7}^(2) } \\ \large{ {(x - 5)}^(2) + {(y + 1)}^(2) = 49 }`

So the answer is B choice.