100 - 7 . ( x - 5 ) = 58

93 . x - 5 = 58

x - 5 =93 : 58 

x - 5 = 1.6

x = 1.6 +5

x = 6.6

100-7.(x-5)=58

     7.(x-5)=100-58

    7.(x-5)=42

        x-5=42:7

        x-5=7

           x=7+5

           x=12

vậy x=12 

100-7x(x-5)=58
 7x(x-5)=100-58=42
x-5= 42:7=6
x=6+5
x=11

a ) 100-7(x-5)=58

=> 7(x-5)=42

=.> x-5 = 6

=> x=11

180-5(x+1)=30

=> 5(x+1)=150

=> x+1=30\

=> x=29

6x-5=613

=> 6x=618

=> x=103

a) \(100-7\left(x-5\right)=58\)

\(\Leftrightarrow7\left(x-5\right)=42\)

\(\Leftrightarrow x-5=6\)

\(\Leftrightarrow x=11\)

b) \(180-5\left(x+1\right)=30\)

\(\Leftrightarrow5\left(x+1\right)=150\)

\(\Leftrightarrow x+1=30\)

\(\Leftrightarrow x=29\)

c) \(6x-5=613\)

\(\Leftrightarrow6x=618\)

\(\Leftrightarrow x=103\)

a) 100-7(x-5)=58

=> 100 - 7x + 35 = 58

=> -7x = -77

=> x = 11

180-5(x+1)=30 

=> 180 - 5x - 5 = 30

=> -5x = -145

=> x = 29

6x-5=613

=> 6x = 618

=> x = 103

\(a,565-\left(6x+70\right)=435\)

                       \(6x+70=565-435\)

                       \(6x+70=130\)

                                  \(6x=130-70\)

                                  \(6x=60\)

                                    \(x=10\)

\(b,100-7\left(x-5\right)=58\)

       \(100-7x+35=58\)

                  \(100-7x=58-35\)

                  \(100-7x=23\)

                                \(7x=100-23\)

                                \(7x=77\)

                                   \(x=11\)

a, 565-(6x+70)=435

6x+70=565-435

6x+70=130

6x=130-70

6x=60

x=60:6

x=6

b, 100-7(x-5)=58

7(x-5)=100-58

7(x-5)=42

x-5=42:7

x-5=6

x=6+5

x=11

\(a,565-\left(6x+70\right)=435\)

                      \(6x+70=130\)

                                 \(6x=130-70\)

                                 \(6x=60\)

                                    \(x=10\)

\(b,100-7\left(x-5\right)=58\)

                 \(7\left(x-5\right)=100-58\)

                 \(7\left(x-5\right)=42\)

                         \(x-5=42:7\)

                         \(x-5=6\)

                                 \(x=6+5\)

                                 \(x=11\)

a. 348 : x = 12 

x = 348 : 12

x = 29

b. 9x - 7 = 119 

9x = 119 + 7 

9x = 126 

x = 126 : 9 

x = 14 

c. 100 - 7 . ( x - 5 ) = 58 

7 . ( x - 5 ) = 100 - 58 

7 . ( x - 5 ) = 42 

x - 5 = 42 : 7

x - 5 = 6

x = 6 + 5

x = 11

d. x không thuộc số tự nhiên

a)348:x=12

x=348:12

x=29

b)9x-7=119

9x=119+7

9x=126

x=126:9

x=14

c)100-7.(x-5)=58

7.(x-5)=100-58

7.(x-5)=42

x-5=42:7

x-5=6

x=6+5

x=11

d)2^x-2.2³=64

2^x-2.8=64

2^x-16=64

2^x=64+16

2^x=80

đề sai

a. 25,97 + 6,54 + 103,46

= 25,97 + (6,54+103,46)

= 25,97+110

= 135,97

b. 50% + 7/12-1/2

= 1/2+7/12-1/2

= (1/2-1/2)+7/12

= 0+7/12

= 7/12

c. 2015.65 + 2015.45 - 2015.10

= 2015. (65+45-10)

= 2015.100

= 201500

2.a.2/3.x+3/4=3

=> 2/3.x=3-3/4

=> 2/3.x=9/4

=> x=9/4:2/3

=> x=9/4.3/2

=> x=27/8

b. 100-7(x-5)=58

=> 7(x-5)=100-58

=> 7(x-5)=42

=> x-5=42:7

=> x-5=6

=> x=6+5

=> x=11

c. x+1/3=7/26 x 13/6

=> x+1/3 = 7/12

=> x=7/12-1/3

=> x=7/12-4/12

=> x=3/12

=> x=1/4

a: Ta có: \(100-7\left(x-5\right)=58\)

\(\Leftrightarrow7\left(x-5\right)=42\)

\(\Leftrightarrow x-5=6\)

hay x=11

b: Ta có: \(12\left(x-1\right):3=4^3+2^3\)

\(\Leftrightarrow12\left(x-1\right)=216\)

\(\Leftrightarrow x-1=18\)

hay x=19