a) x bình (x-3) + 12 – 4x = 0
b) ( 2x + 3) (x-1)+(2x-3)(1-x)=0
c) (5x-4)tất cả bình -49x bình =0
d) x bình + 3x – 10 =0
giúp mình vs mình cần gấp lắm
a) x bình (x-3) + 12 – 4x = 0
b) ( 2x + 3) (x-1)+(2x-3)(1-x)=0
c) (5x-4)tất cả bình -49x bình =0
d) x bình + 3x – 10 =0
giúp mình vs mình cần gấp lắm
a) $x^2(x-3)+4(3-x)=0$
$\Rightarrow (x-3)(x^2-4)=0$
$\Rightarrow (x-3)(x-2)(x+2)=0$
$\Rightarrow \left[ \begin{array}{l} x=3 \\x=\pm2 \end{array} \right .$
b) $(x-1)[2x+3-(2x-3)]=0$
$\Rightarrow 6(x-1)=0$
$\Rightarrow x=1$
c) $(5x-4)^2-49x^2=0$
$\Rightarrow (5x-4-7x)(5x-4+7x)=0$
$\Rightarrow (-4-2x)(12x-4)=0$
$\Rightarrow \left[ \begin{array}{l}x=-2 \\ x=\dfrac{1}{3}\end{array} \right .$
d) $x^2+3x-10=0$
$\Rightarrow x^2-2x+5x-10=0$
$\Rightarrow x(x-2)+5(x-2)=0$
$\Rightarrow (x-2)(x+5)=0$
$\Rightarrow \left[\begin{array}{l} x=2\\x=-5 \end{array} \right .$