Đáp án:
Giải thích các bước giải
b) x - 5√x + 6 = x - 2√x - 3√x + 6 = √x (√x - 2) - 3(√x - 2) = (√x - 2) (√x - 3)
hay x - 5√x + 6 = x - 3√x - 2√x + 6 = √x(√x - 3) - 2(√x - 2) = (√x - 2) (√x - 3)
c) x + 5√x + 6 = x + 2√x + 3√x + 6 = √x(√x + 2) + 3(√x + 2) = (√x + 3) (√x + 2)
hay x + 5√x + 6 = x + 3√x + 2√x + 6 = √x(√x + 3) + 2(√x + 3) = (√x + 3) (√x + 2)
d) 2x - √x - 1= 2x - 2√x + √x - 1 = 2√x (√x - 1) + (√x - 1) = (2√x + 1) (√x - 1)
hay 2x - √x - 1= 2x + √x - 2√x - 1 = √x (2√x + 1) - (2√x + 1) = (2√x + 1) (√x - 1)