Question

[hoangtuvi]

tìm x theo hằng đẳng thức :(x+1)(x+2)(x+5)-x²(x+8)=27

Answer 1

[Kinomoto Sakura]

(x + 1)(x + 2)(x + 5) − x²(x + 8) = 27

x² + 2x + x + 2(x + 5) − x³ − 8x² = 27

x²(x + 5) + 2x(x + 5) + x(x + 5) + 2(x + 5) − x³ − 8x² = 27

x³ + 5x² + 2x² + 10x + x² + 5x + 2x + 10 − x³ − 8x² = 27

17x + 10 = 27

17x = 17

    x = 17 : 17

    x = 1

Vậy x = 1