Question

Tìm x, biết:

(x² - 5) (x + 2) + 5x = 2x² + 17

Mình đang cần gấp

Answer 1

\(\left(x^2-5\right)\left(x+2\right)+5x=2x^2+17\)

\(\Leftrightarrow x^3-5x+2x^2-10+5x=2x^2+17\)

\(\Leftrightarrow x^3-10=17\)

\(\Leftrightarrow x^3=27\)

\(\Leftrightarrow x=\sqrt[3]{27}=3\)

Answer 2

=> x^3 -5x+2x^2-10+5x=2x^2+17

=>x^3+2x^2-5x+5x=2x^2+27

=>x^3=27

=>x=3

mình ko chắc lắm

Answer 3

(x² - 5)(x + 2) + 5x = 2x² + 17

x³ + 2x² - 5x - 10 + 5x = 2x² + 17

x³ + 2x² - 10 = 2x² + 17

x³ - 10 = 17

x³ = 17 + 10

x³ = 27

x³ = 3³

x = 3