What equation represents a circle with a center at (-4,9) and a diameter or 10 units

(x + 4)² + (y - 9)² = 25

Step-by-step explanation:

The equation of a circle in standard form is

(x - h)² + (y - k)² = r²

where (h, k) are the coordinates of the centre and r is the radius

Here (h, k) = (- 4, 9) and r = 10 ÷ 2 = 5 , thus

(x - (- 4))² + (y - 9)² = 5² , that is

(x + 4)² + (y - 9)² = 25 ← equation of circle

let soccer = x and golf = y

part a

1st equation: x + y = 125

2nd equation: x = y +45

part b

replace x in the 1st equation with the 2nd one:

y + 45 + y = 125

simplify:

2y + 45 = 125

subtract 45 from each side:

2y = 80

divide both sides by 2:

y = 80/2

y = 40

she plays golf for 40 minutes.

part c

no because she plays soccer for 45 minutes longer than golf 40 +45 =   85 minutes, not 80 minutes.

answer: a and b

step-by-step explanation: