Question

tìm x

a) (x+73)-315=217

b) 2727:(12.x-91)=27

c) x+x.4,5:3+x.7:2=235

d) (x+1)+(x+3)+(x+5)+...+(x+99)=3000

dấu chấm là nhân

giải 4 câu này giúp mình! mình cần gấp

Answer 1

a: =>x-242=217

=>x=459

b: =>12x-91=101

=>12x=192

=>x=16

c: =>x+1,5x+3,5x=235

=>6x=235

hay x=235/6

Answer 2

`(x+73)-315=217`

`x+73=217+315`

`x+73=332`

`x=332-73`

`x=259`

______________________________

`2727:(12.x-91)=27`

`12x-91=2727:27`

`12x-91=101`

`12x=101+91`

`12x=192`

`x=192:12`

`x=16`

____________________________________

`x+x.4,5:3+x.7:2=235`

`x+ 1,5x + 3,5x=235`

`1x+1,5x+3,5x=235`

`(1+1,5+3,5)x=235`

`6x=235`

`x=235:6`

`x=235/6`

________________________________________

`(x+1)+(x+3)+(x+5)+...+(x+99)=3000`

`x+1+x+3+....+x+99=3000`

`(x+x+....+x)+(1+3+....+99)=3000`

Số hạng:

`(99-1)/2+1=50(số)`

Tổng:

`(99+1)xx50:2=2500`

`=>50x+2500=3000`

`50x=3000-2500`

`50x=500`

`x=500:50`

`x=10`