Đáp án+Giải thích các bước giải:
`a) (2x+1)²-(3-2x)²+4=0`
`⇔4x²+4x+1-(9-12x+4x²)+4=0`
`⇔4x²+4x+1-9+12x-4x²+4=0`
`⇔16x-4=0`
`⇔16x=4`
`⇔x=1/4`
Vậy `S={1/4}`
`b) (x-1)³+(2-x)(4+2x+x²)+3x(x+2)=17`
`⇔x³-3x²+3x-1+2³-x³+3x²+6x=17`
`⇔9x+7=17`
`⇔9x=10`
`⇔x=10/9`
Vậy `S={10/9}`
`c) (x+2)(x²-2x+4)-x(x²-2)=15`
`⇔x³+2³-x³+2x=15`
`⇔8+2x=15`
`⇔2x=7`
`⇔x=7/2`
Vậy `S={7/2}`
Chúc bn hc tốt🥰
$\text{#LinhSad}$
