Tìm x biết: a, A= (3 – 5x).(3 + 5x)+(5x – 2) mũ 2=11 08/08/2021 Bởi Reagan Tìm x biết: a, A= (3 – 5x).(3 + 5x)+(5x – 2) mũ 2=11
$(3-5x)(3+5x)+(5x-2)^2=11$ $⇔9-25x^2+25x^2-20x+4=11$ $⇔-25x^2+25x^2-20x=11-9-4$ $⇔-20x=-2$ $⇔x=\frac{1}{10}$ Vậy $x=\frac{1}{10}$. Bình luận
$(3-5x)(3+5x)+(5x-2)^2=11$
$⇔9-25x^2+25x^2-20x+4=11$
$⇔-25x^2+25x^2-20x=11-9-4$
$⇔-20x=-2$
$⇔x=\frac{1}{10}$
Vậy $x=\frac{1}{10}$.
(3 – 5x).(3 + 5x)+(5x – 2)^2=11
<=>9-25^2+25^2-20x+4=11
<=>13-20x=11
<=>-20x=-2
<=>x=1/10