Question

Aflati valoarea numarului natural x,stiind ca: a) 2+2•[1+2•(1+2x)]=80 b) (x+1)(x+2)=56 c) (x:50+30):6-6=0 d) [2•(x+2)•5+3•(x+2)]•7=273

Answer 1

a) 2+2•[1+2•(1+2x)]=80
2•[1+2•(1+2x)]=78
1+2•(1+2x)=39
2•(1+2x)=38
1+2x=19
2x=18
x=9

b) (x+1)(x+2)=56
(x+1)(x+2)=7×8
x+1=7   x=6
x+2=8   x=6


c) (x:50+30):6-6=0
(x:50+30):6=6
x:50+30=36
x:50=6
x=300

d) [2•(x+2)•5+3•(x+2)]•7=273
10x+20+3x+6=39
 13x=39-26
13x=13
x=1