Question

 Tìm x thuộc N biết :

a) (x-15)x15=0

b) 32(x-10)=32

c)315 (125-x)=435

d) (x-15)-75=0

e) 575-(6x 70)=445

g)x-105:21=15'

Answer 1

câu d mk làm sai rồi

d) (x-15)-75=0

x-15=0+75=75

x=75+15=90

 

Answer 2

a, x= 15

b, x = 11

c, x =?

d, x = 90

e, ?

g, x=20

Answer 3

a) (x-15)x15=0

=>x-15=0

    x=0+15=15

b) 32(x-10)=32

x-10=32:32=1

x=1+10=11

c)315 (125-x)=435

125-x=435-315=120

x=125-120=5

d) (x-15)-75=0

=>x-15=0

    x=0+15=0

e) 575-(6x 70)=445

6x70=575-445=130

6x=130:70=13/7

x=13/7:6=13/42

g)x-105:21=15'

x-5=15

x=15+5=20

**** nhé

Answer 4

555..55.55..5.5.5555.5.5.5..5.5.5.5.5. chia cho 200/32 bằng mấy