Question

Tìm x biết : (x + 3)² + (4 + x).(4 - x) = 10

Answer 1

(x + 3)^2 + (4 + x)(4 - x) = 10

x^2 + 6x + 9 + 16 - x^2 = 10

6x + 25 = 10

6x = 10 - 25

6x = -15

x = -15/6 = -5/2

Answer 2

 Ta có ( x+3)^2 +(4+x)(4-x) =10

   => x^2 + 6x +9 +16- x^2 =10

   => 6x+25 =10

   => 6x= -15

   => x=-5/2

Vậy x=-5/2

Answer 3

 Ta có ( x+3)^2 +(4+x)(4-x) =10

   => x^2 + 6x +9 +16- x^2 =10

   => 6x+25 =10

   => 6x= -15

   => x=-5/2

Vậy x=-5/2