Question

Afla valoarea numarului necunoscut din urmatoare expresii:402+[1002:3-(100+a)×2]:14=408
40+90:[9+48:(a+6)]=46
[(38×a+120):25×54]-980=100
7777-(77:7+a-7777:7+777)×7=777
[80×(a:16-64)×60-3980]:4=3805

Answer 1

Răspuns:

402+[1002:3-(100+a)×2]:14=408

402+[334-(100+a)X2]:14=408

[334-(100+a)X2]:14=408-402

[334-(100+a)X2]:14=6

[334-(100+a)X2]=6x14

[334-(100+a)X2]=84

(100+a)x2=334-84

(100+a)X2=250

(100+a)=250:2

100+a=125

a=125-100

a=25

40+90:[9+48:(a+6)]=46

90:[9+48:(a+6)]=46-40

90:[9+48:(a+6)=6

[9+48:(a+6)=90:6

[9+48:(a+6)=15

48:(a+6)=15-9

48:(a+6)=6

a+6=48:6

a+6=8

a=8-6

a=2

[(38×a+120):25×54]-980=100

[(38xa+120):25x54]=100+980

[(38xa+120):25x54]=1080

(38xa+120):25=1080:54

(38xa+120):25=20

(38xa+120)=20x25

(38xa+120)=500

38xa=500-120

38xa=380

a=380:38

a=10

7777-(77:7+a-7777:7+777)×7=777

7777-(11+a-1111+777)x7=777

(11+a-1111+777)x7=7777-777

(11+a-1111+777)x7=7000

(11+a-1111+777)=7000:7

11+a-1111+777=1000

a=1000-777+1111-11

a=1323

[80×(a:16-64)×60-3980]:4=3805

[80×(a:16-64)×60-3980]=3805x4

80x(a:16-64)x60-3980=15220

80x(a:16-64)x60=15230+3980

80x(a:16-64)x60=19200

80x(a:16-64)=19200:60

80x(a:16-64)=320

a:16-64=320:80

a:16-64=4

a:16=4+64

a:16=68

a=68x16

a=1088