Question

Tìm x biết ( x- 3 ) ² - 2 = \(\dfrac{14}{9}\)

Answer 1

( x - 3 )² -2 = \(\dfrac{14}{9}\)

( x - 3 )² = \(\dfrac{14}{9}+2\)

( x - 3 )² = \(\dfrac{32}{9}\)

( x - 3 )² = \(\left(\dfrac{4\sqrt{2}}{3}\right)^2\)

⇒(x - 3)= ............

Answer 2

Ta có: (x-3)² - 2 =\(\dfrac{14}{9}\)

Nên (x-3)²=\(\dfrac{14}{9}+2=\dfrac{32}{9}\)

Do đó: x-3= \(\sqrt{\dfrac{32}{9}}\) hoặc x-3= \(-\sqrt{\dfrac{32}{9}}\)

Suy ra: x= \(\sqrt{\dfrac{32}{9}}\)+3 hoặc x= \(-\sqrt{\dfrac{32}{9}}\)+3