Question

125х^3-75х^2+15х-1=0
64х^3+144х^2+108х+27=0
решить уравнение. ПОМОГИТЕ ПЖ. ​

Answer 1

(a - b)³ = a³ - 3a²b + 3ab² - b³

(a + b)³ = a³ + 3a²b + 3ab² + b³

125х^3-75х^2+15х-1=0

(5x)³ - 3*(5x)²*1 + 3*5x*1² - 1³ = 0

(5x - 1)³ = 0

5x - 1 = 0

x = 1/5

64х^3+144х^2+108х+27=0

(4x)³ + 3*(4x)²*3 + 3*4x*3² + 3³ = 0

(4x + 3)³ = 0

4x + 3 = 0

x = -3/4