:))

(2x +3) .(x-5)=4x^2 + 6x

<=> 2x^2-7x-15=4x^2+6x

<=>2x^2 +13x +15 =0

<=> x = -3/2 hoặc x = -5

bệnh cận thị

cách khắc phục

ct nek  $C\%=\frac{m_{ct}}{m_{dd}}.100\%$

3x-2x-1-x+3x+1=2<=>(3x-2).(x+1)(x-1)(x+1)-(x+3)(x-1)(x+1)(x-1)=2<=>3x2+x-2(x-1)(x+1)-x2+2x-3(x-1)(x+1)=2<=>2x2-x+1(x-1)(x+1)=2<=>2x2-x+1=2(x-1)(x+1)<=>2x2-x+1=2x2-2<=>x-3=0<=>x=3