a) 7xy² - 14x³ = 7x(y² - 2x²) = 7x(y + √2x)(y - √2x)б) 25x - x³ = x(25 - x²) = x(5 + x)(5 - x)в) 5a - ab + 5c - cb = a(5 - b) - c(b - 5) = (a - c)(5 - b)
a) 7xy² - 14x³ = 7x(y² - 2x²) = 7x(y + √2x)(y - √2x)
x(x-4) = (x+3)²б) 25x - x³ = x(25 - x²) = x(5 + x)(5 - x)
в) 5a - ab + 5c - cb = a(5 - b) - c(b - 5) = (a - c)(5 - b)
x² - 4x = x² + 6x + 9
-4x = 6x + 9
-10x = 9
x = -9/10