Question

tìm x :

a, 2 x X - 18 = 15 x 2

b, x + 36 : 12 = 78

c,100 : X - 25 = 5 x 5

Answer 1

`a, 2 xx x -18 = 15 xx 2`

`2 xx x - 18 = 30`

`2 xx x = 48`

`x = 24`

`b, x + 36 : 12 = 78`

`x + 3 = 78`

`x = 75`

`c, 100 : x - 25 = 5 xx 5`

`100 : x - 25 = 25`

`100 : x = 50`

`x = 100/50 = 2`

Answer 2

a: =>2x-18=30

=>2x=48

hay x=24

b: =>x+3=78

=>x=75

c: =>100:x=25+25=50

=>x=2

Answer 3

a, 2 x X - 18 = 15 x 2

2 x X - 18 = 30

2 x X = 30 + 18

2 x X = 48

X = 48 : 2

X = 24

Vậy X = 24

b, x + 36 : 12 = 78

x + 36 = 78 x 12

x + 36 = 936

x = 936 - 36 

x = 900

Vậy x = 900

c,100 : X - 25 = 5 x 5

100 : X - 25 = 25

100 : X = 25 + 25

100 : X = 50

X = 100 : 50

X = 50

Vậy X = 50