Question

4-9(2-5x)^2=0 Срочно

Answer 1

4 - 9(4 - 20х + 25х^2) = 0
4 - 36 + 180х - 225х^2 = 0
- 225х^2 + 180х - 32 = 0, k = 90

D = k^2 - ac = 8100 - 225* 32 = 900 = 30^2 => D > 0 => уравнение имеет два корня

x1 = (-k + sqrt (D)) / a = (-90 + 30)/(-225) = -60/-225 = 4/15
x2 = (-k - sqrt (D)) / a = (-90 - 30)/(-225) = -120/-225 = 8/15