a: \(x-43=\left(35-x\right)-48\)

=>\(x-43=35-x-48\)

=>\(x-43=-x-13\)

=>\(x+x=-13+43\)

=>2x=30

=>x=30/2=15

b: \(305-x+14=48+\left(x-23\right)\)

=>\(319-x=48+x-23=25+x\)

=>\(x+25=319-x\)

=>\(x+x=319-25\)

=>\(2x=294\)

=>\(x=\dfrac{294}{2}=147\)

c: \(-\left(-x-6+85\right)=\left(x+51\right)-54\)

=>\(-\left(-x+79\right)=x+51-54\)

=>x-79=x-3

=>-79=-3(vô lý)

=>\(x\in\varnothing\)

d: \(-\left(35-x\right)-\left(37-x\right)=33-x\)

=>\(-35+x-37+x=33-x\)

=>2x-72=-x+33

=>\(2x+x=33+72\)

=>3x=105

=>\(x=\dfrac{105}{3}=35\)

1,x-43=(35-x)-48

=>x-43=35-x-48

=>x+x=35-48+43

=>2x=30

=>x=15

Vậy x=15

2,305-x+14=48+(x-23)

=>305-x+14=48+x-23

=>305+14+23-48=x+x

=>294=2x

=>x=294:2

=>x=147

3,-(x-6+85)=(x+51)-54

=>-x+6-85=x+51-54

=>6-85-51+54=x+x

=>-76=2x

=>x=(-76):2

=>x=-38

4,-(35-x)-(37-x)=33-x

=>-35+x-37+x=33-x

=>-35+(-37)+(-33)=-x-x-x

=>-105=-3x

=>x=(-105):(-3)

=>x=35

5,13-\(|x|=|-4|\)

=>13-\(|x|\)=4

=>13-4=\(|x|\)

=>9=\(|x|\)

=>x=9 hoặc x=-9

5) 13 - |x| = |-4|

=> 13 - |x| = 4

|x| = 13-4 = 9

Vậy x=9 hoặc x=-9

4) - (35-x) - (37-x) = 33-x

<=>-35 + x - 37 + x = 33-x

<=> -35 - 37 + x + x = 33-x

-72 + 2x = 33 - x

Theo quy tắc chuyển vế, ta có

-72 - 33 = - 2x + x

-105 = - (2x+x)

-105 = -3x

=> x = (-105) : (-3) = 35

Vậy x=35

Mk chỉ làm đc hai câu thôi. Mk có việc nên ko thể làm tiếp đc cho bạn nữa nha...

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Nhiều quá bạn ơi

1.\(x-43=\left(35-x\right)-48\)

\(\Rightarrow x-43=35-x-48\)

\(\Rightarrow2x=35+43-48\)

\(\Rightarrow2x=30\)

\(\Rightarrow x=15\)

2.\(305-x+14=48+\left(x-23\right)\)

\(\Rightarrow305-x+14=48+x-23\)

\(\Rightarrow305+14=48+x+x-23\)

\(\Rightarrow2x+25=319\)

\(\Rightarrow2x=294\)

\(\Rightarrow x=147\)

3.\(-\left(x-6+85\right)=\left(x+51\right)-54\)

\(\Rightarrow-x+6-85=x+51-54\)

\(\Rightarrow6-85=x+x+51-54\)

\(\Rightarrow2x-3=-79\)

\(\Rightarrow2x=-76\)

\(\Rightarrow x=-38\)

4.\(-\left(35-x\right)-\left(37-x\right)=33-x\)

\(\Rightarrow-35+x-37+x=33-x\)

\(\Rightarrow2x-72=33-x\)

\(\Rightarrow3x=105\)

\(\Rightarrow x=35\)

5.\(13-\left|x\right|=\left|-4\right|\)

\(\Rightarrow13-\left|x\right|=4\)

\(\Leftrightarrow\left[{}\begin{matrix}13-x=4\\13+x=4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=9\\x=-9\end{matrix}\right.\)

Lê Quang Phúc 

bài 1:Tính nhanh

b)58+42+32nhân 8+5 nhân 16

c)(42 nhân 43+46nhân 57+43)-360:4

bài 2:tìm x

a)890:x=35 dư 15

c)1482:x+23=80

a)128-3(x+4)=23 

    125.(x+4)=23

             ( x +4)=23 : 125

             x+4 = 0,184

                x = 0,184 -4

                  x = -3 .816

theo mềnh nhóe ( làm từng câu )

c: =>12x-64=32

=>12x=96

hay x=8

g: =>3x-16=14

hay x=10

e: =>5(x+4)=85

=>x+4=17

hay x=13

a) Ta có: x-43=(35-x)-48

⇔x-43=35-x-48

⇔x-43=-x-13

⇔x-43+x+13=0

⇔2x-30=0

⇔2(x-15)=0

mà 2≠0

nên x-15=0

hay x=15

b) Ta có: 305-x+14=48+(x-23)

⇔319-x=48+x-23

⇔319-x=x+25

⇔319-x-x-25=0

⇔-2x+294=0

⇔-2x=-294

hay x=147

Vậy: x=147

c) Ta có: -(x-6+85)=(x+51)-54

⇔-x+6-85=x+51-54

⇔-x-79=x-3

⇔-x-79-x+3=0

⇔-2x-76=0

⇔-2x=76

hay x=-38

Vậy: x=-38

d) Ta có: -(35-x)-(37-x)=33-x

⇔-35+x-37+x-33+x=0

⇔3x-105=0

⇔3(x-35)=0

mà 3≠0

nên x-35=0

hay x=35

Vậy: x=35

e) Ta có: 13-|x|=|-4|

⇔13-|x|=4

⇔|x|=9

⇔x∈{9;-9}

Vậy: x∈{9;-9}

f) Ta có: |x|-3+6=16

⇔|x|+3=16

⇔|x|=13

hay x∈{-13;13}

Vậy: x∈{-13;13}

g) Ta có: 35-|2x-1|=14

⇔|2x-1|=21

⇔\(\left[{}\begin{matrix}2x-1=21\\2x-1=-21\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=22\\2x=-20\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=11\\x=-10\end{matrix}\right.\)

Vậy: x∈{11;-10}

h) Ta có: |3x-2|+5=9-x

⇔|3x-2|+5-9+x=0

⇔|3x-2|-4+x=0

⇔|3x-2|=0-(-4+x)

⇔|3x-2|=4-x

⇔\(\left[{}\begin{matrix}3x-2=4-x\\3x-2=x-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x-2-4+x=0\\3x-2-x+4=0\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}4x-6=0\\2x+2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}4x=6\\2x=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\frac{3}{2}\left(ktm\right)\\x=-1\left(tm\right)\end{matrix}\right.\)

Vậy: x=-1