Question

tìm x biết

\(x\left(x+1\right).\left(x+6\right)-x^3=5x\)

Answer 1

x(x + 1)(x + 6) - x³ = 5x

=> x(x + 1)(x + 6) = 5x + x³

=> x(x + 1)(x + 6) = x.(5 + x²)

=> (x + 1)(x + 6) = 5 + x²

=> (x + 1).x + (x + 1).6 = 5 + x²

=> x² + x + 6x + 6 = 5 + x²

=> 7x + 6 = 5

=> 7x = 5 - 6

=> 7x = -1

=> x = -1/7

Vậy x = -1/7

Answer 2

Nhân 2 đa thức

\(=\left(x^2+x\right)\left(x+6\right)-x^3\)

\(=x^3+6x^2+x^2+6x-x^3\)
\(=7x^2+6x-x^3=5x\)

Answer 3

x(x + 1)(x + 6) - x³ = 5x

=> x(x + 1)(x + 6) = 5x + x³

=> x(x + 1)(x + 6) = x.(5 + x²)

=> (x + 1)(x + 6) = 5 + x²

=> (x + 1).x + (x + 1).6 = 5 + x²

=> x² + x + 6x + 6 = 5 + x²

=> 7x + 6 = 5

=> 7x = 5 - 6

=> 7x = -1

=> x = -1/7

Vậy x = -1/7

Answer 4

cấy ni học rồi mà dừ quên té rồi

Answer 5

           Bài làm :

Ta có :

x(x + 1)(x + 6) - x³ = 5x

<=> x(x + 1)(x + 6) = 5x + x³

<=> x(x + 1)(x + 6) = x.(5 + x²)

<=> (x + 1)(x + 6) = 5 + x²

<=> (x + 1).x + (x + 1).6 = 5 + x²

<=> x² + x + 6x + 6 = 5 + x²

<=> 7x + 6 = 5

<=> 7x = 5 - 6

<=> 7x = -1

<=> x = -1/7

Vậy x = -1/7