x^2 +10x +25 -4=0 => (x^2 +10x +25)-4=0 => (x+5)^2 -2^2=0 => (x+5-2)(x+5+2)=0 => (x+3)(x+7)=0 => $\left[\begin{matrix} x+3=0\\ x+7=0\end{matrix}\right.$ => $\left[\begin{matrix} x=-3\\ x=-7\end{matrix}\right.$ Vậy x in {-7;-3} Trả lời
x^2 + 10x + 25 -4 =0 ( x^2 + 2.5.x + 5^2 ) – 4=0 ( x+ 5)^2 -4=0 ( x+ 5-2 ) ( x + 5+2 )=0 ( x + 3 ) ( x + 7 ) =0 => TH1 : x+ 3=0=> x=-3 TH2 : x + 7=0=> x = -7 Vậy x\in { – 7 ; -3 } Trả lời
2 bình luận về “X^2 + 10x +25 – 4= 0”