Jawabanmu

2014-06-24T16:58:54+07:00
R = (ax₁ + by₁ + c) / √a²+b²
  = (3.5 + (-4)(-2) + 7) / √3²+(-4)²
  = (15 + 8 + 7) / √9+16
  = 30 / 5 = 6

(x - x₁)² + (y - y₁)² = r²
(x - 5)² + (y + 2)² = 6²
x² - 10x + 25 + y² + 4y + 4 = 36
x² + y² - 10x + 4y - 7 = 0