tìm x a, -(x-19)-(x-17)+3x-25=-9 b,(x-3)+(5-2x)=-119+(-7) c,|2x-1|=(59-19)-(-8-12) 05/11/2021 Bởi Lydia tìm x a, -(x-19)-(x-17)+3x-25=-9 b,(x-3)+(5-2x)=-119+(-7) c,|2x-1|=(59-19)-(-8-12)
`a)-(x-19)-(x-17)+3x-25=-9` `→-x+19-x+17+3x-25=-9` `→-x-x+3x=-9-19-17+25` `→x=-20` Vậy `x=-20` `b)(x-3)+(5-2x)=-119+(-7)` `→x-3+5-2x=-126` `→x-2x=-126+3-5` `→-x=-128` `→x=128` Vậy `x=128` `c)|2x-1|=(59-19)-(-8-12)` `→|2x-1|=40-(-20)` `→|2x-1|=60` `→` \(\left[ \begin{array}{l}2x-1=60\\2x-1=-60\end{array} \right.\) `→` \(\left[ \begin{array}{l}2x=61\\2x=-59\end{array} \right.\) `→` \(\left[ \begin{array}{l}x=\dfrac{61}{2}\\x=\dfrac{-59}{2}\end{array} \right.\) Vậy `x∈{61/2;-59/2}` Bình luận
a)-(x-19)-(x-17)+3x-25=-9 ⇔-x+19-x+17+3x-25+9=0 ⇔x+20=0 ⇔x=-20 b) (x-3)+(5-2x)=-119+(-7) ⇔x-3+5-2x+119+7=0 ⇔-x+128=0 ⇔-x=-128 ⇔x=128 c) |2x-1|=(59-19)-(-8-12) ⇔|2x-1|=60 ⇔2x-1=60 hoặc 2x-1=-60⇔x=61/2 hoặc x=-59/2 Bình luận
`a)-(x-19)-(x-17)+3x-25=-9`
`→-x+19-x+17+3x-25=-9`
`→-x-x+3x=-9-19-17+25`
`→x=-20`
Vậy `x=-20`
`b)(x-3)+(5-2x)=-119+(-7)`
`→x-3+5-2x=-126`
`→x-2x=-126+3-5`
`→-x=-128`
`→x=128`
Vậy `x=128`
`c)|2x-1|=(59-19)-(-8-12)`
`→|2x-1|=40-(-20)`
`→|2x-1|=60`
`→` \(\left[ \begin{array}{l}2x-1=60\\2x-1=-60\end{array} \right.\)
`→` \(\left[ \begin{array}{l}2x=61\\2x=-59\end{array} \right.\)
`→` \(\left[ \begin{array}{l}x=\dfrac{61}{2}\\x=\dfrac{-59}{2}\end{array} \right.\)
Vậy `x∈{61/2;-59/2}`
a)-(x-19)-(x-17)+3x-25=-9
⇔-x+19-x+17+3x-25+9=0
⇔x+20=0
⇔x=-20
b) (x-3)+(5-2x)=-119+(-7)
⇔x-3+5-2x+119+7=0
⇔-x+128=0
⇔-x=-128
⇔x=128
c) |2x-1|=(59-19)-(-8-12)
⇔|2x-1|=60
⇔2x-1=60 hoặc 2x-1=-60⇔x=61/2 hoặc x=-59/2