Question

Tìm x biết

a, 5 ( x + 35 ) = 515

b, 12x - 33 = 3² . 3³

c, 6.x - 5 = 9

d, 4.( x - 12 ) + 9 = 17

Answer 1

đây là cách giải của mk:

a, 5(x + 35) = 515

=> x + 35 = 515 : 5

=> x + 35 = 103

=> x        = 103 - 35

=> x        = 68

b, 12x - 33 = 3² . 3³

=> 12x - 33 = 3^{2 + 3}

=> 12x - 33 = 3⁵

=> 12x - 33 = 243

=> 12x       = 243 + 33

=> 12x       = 276

=>    x       = 276 : 12

=>    x       =  23

c, 6 . x - 5 = 9

=> 6 . x    = 9 + 5

=> 6 . x    = 14

=>     x    = 14 : 6

=>     x    = \(\frac{2}{3}\)

d, 4(x - 12) + 9 = 17

=> 4(x - 12)     = 17 - 9

=> 4(x - 12)     = 8

=> 4 . x - 12    = 8

=> 4 . x           = 8 + 12

=> 4 . x           = 20

=>     x            = 20 : 4

=>     x            = 5

Answer 2

a, 5 ( x + 35 ) = 515

x + 35 = 515 : 5

x + 35 = 103

      x = 103 - 35

      x = 68

b, 12x - 33 = 3² . 3³

12x - 33 = 3⁵

12x - 33 = 243

12x = 243 + 33

12x = 276

x = 276 : 12

x = 23

c, 6.x - 5 = 9

6x = 9 + 5

6x = 14

x = 14 : 6

x = \(\frac{7}{3}\)

d, 4.( x - 12 ) + 9 = 17

4 . ( x - 12 ) = 17 - 9

4 . ( x - 12 ) = 8

x - 12 = 8 : 4

x - 12 = 2

x = 2 + 12

x = 14

Answer 3

\(5\left(x+35\right)=515\)

\(\Rightarrow x+35=103\)

\(\Rightarrow x=103-35\)

\(\Rightarrow x=68\)

Answer 4

a,x+35=515:5

x+35=103

x=103+35=138

b,12x-13=243

12x=243+13=256

x=256:12=

c,6x=9+5

6x=14

x=14:6

d,4.(x-12)=17-9

4.(x-12)=8

x-12=8:4

x-12=2

x=2+12=14

Answer 5

450-x+7 .3=30

115-15: 3x-5=100