a) 30-2x=x-2021
b) x(2x-1)-2(x+2)^2=2019
c) (x-3)^2-2021x+6063=0
d) 12/x^2-4 – x+1/x+2 + x+7/x+2=0
e) 7x/6 +2x < 16-x/5 -12
a) 30-2x=x-2021 b) x(2x-1)-2(x+2)^2=2019 c) (x-3)^2-2021x+6063=0 d) 12/x^2-4 – x+1/x+2 + x+7/x+2=0 e) 7x/6 +2x < 16-x/5 -12
By Adalyn
`a,\ 30-2x=x-2021`
`<=>30-2x-x+2021=0`
`<=>2025-3x=0`
`<=>-3x=-2025`
`<=>x=2025/3`
Vậy…
`b,\ x(2x-1)-2(x+2)^2=2019`
`<=>2x^2-1-2(x^2+4x+4)=2019`
`<=>2x^2-1-2x^2-8x-8=2019`
`<=>-8x-9=2019`
`<=>-8x=2028`
`<=>x=(-507)/2`
Vậy…
`c, (x-3)^2-2021x+6063=0`
`<=>x^2-6x+9-2021x+6063=0`
`<=>x^2−2027x+6072=0`
`<=>(x−2024)(x−3)=0`
`<=>(x−2024)(x−3)=0`
$⇔\begin{cases}x−2024=0 \\ x−3=0 \end{cases}$
$⇔\begin{cases}x=2024\\ x=3 \end{cases}$
Vậy…
`d,\ 12/(x^2-4)-(x+1)/(x+2)+(x+7)/(x+2)=0`
`<=>12/(x^2-4)-((x+1)(x-2))/(x^2-4)+((x+7)(x-2))/(x+2)=0`
`<=>12-(x+1)(x-2)+(x+7)(x-2)=0`
`<=>12-(x^2−x−2)+x^2+5x−14=0`
`<=>12-x^2+x+2+x^2+5x−14=0`
`<=>6x=0`
`<=>x=0`
Vậy…
`e,` Mk ko rõ đề nên bỏ qua nha.
$#Blink$ $\boxed{\text{@Rosé}}$