làm ơn giúp mình câu này với
(x+1/2018) + (x+2/2017) + (x+3/2016) +( x+4/2015)=-4
làm ơn giúp mình câu này với (x+1/2018) + (x+2/2017) + (x+3/2016) +( x+4/2015)=-4
By Katherine
By Katherine
làm ơn giúp mình câu này với
(x+1/2018) + (x+2/2017) + (x+3/2016) +( x+4/2015)=-4
$\frac{x+1}{2018}$ + $\frac{x+2}{2017}$ + $\frac{x+3}{2016}$ + $\frac{x+4}{2015}$ = -4
⇒ $\frac{x+1}{2018}$ + $\frac{x+2}{2017}$ + $\frac{x+3}{2016}$ + $\frac{x+4}{2015}$ + 4 = 0
⇒ ( $\frac{x+1}{2018}$ + 1 ) + ( $\frac{x+2}{2017}$ + 1 ) + ( $\frac{x+3}{2016}$ + 1 ) + ( $\frac{x+4}{2015}$ + 1 ) = 0
⇒ $\frac{x+2019}{2018}$ + $\frac{x+2019}{2017}$ + $\frac{x+2019}{2016}$ + $\frac{x+2019}{2015}$ = 0
⇒ ( x + 2019 ) . ( $\frac{1}{2018}$ + $\frac{1}{2017}$ + $\frac{1}{2016}$ + $\frac{1}{2015}$ ) = 0
⇒ x + 2019 = 0 ( vì $\frac{1}{2018}$ + $\frac{1}{2017}$ + $\frac{1}{2016}$ + $\frac{1}{2015}$ $\neq$ 0 )
⇒ x = – 2019
Đáp án:
Giải thích các bước giải:
`(x+1)/2018 + (x+2)/2017 + (x+3)/2016 +( x+4)/2015=-4`
`=>(x+1)/2018 + (x+2)/2017 + (x+3)/2016 +( x+4)/2015+4=0`
`=>((x+1)/2018+1) + ((x+2)/2017 +1)+( (x+3)/2016 +1)+(( x+4)/2015+1)=0`
`=>((x+1)/2018+2018/2018) + ((x+2)/2017 +2017/2017)+( (x+3)/2016 +2016/2016)+(( x+4)/2015+2015/2015)=0`
`=>(x+2019)/2018 + (x+2019)/2017 + (x+2019)/2016 +( x+2019)/2015=0`
`=>(x+2019)(1/2018 + 1/2017 + 1/2016 +1/2015)=0`
`=>x+2019=0`
`=>x=-2019`