Question

Sa se rezolve in multimea numerelor naturale ectuatiile a)3x(2x+5)+19=82;
b)7x(3x-5)+23=112;
c)5x(4x=7)-32=63;
d)51-2x(7x+2)=19;
e)9x(5-3x)+71+89;
f)(4x+5):13+36=41;
g)(3x+2):4-2=3;
h)(3x-11):2+12=20;

Answer 1

3x(2x+5)+19=82
3X (2X+5)=82-19=63
2X+5=63:3
2X+5=21
2X=21-5 =16 
X=16:2 => X=8 

7X(3X-5)+23=112
7x (3x-5)=112-23= 89
21x-5=89
21x=89-5=>21x=84 
x=81:21=>x=4

Si faci asa la toate..
SUCCES

Answer 2

a) 6x+15x+19=82 ; 21x=82-19 ; 21x=63 ; x=3.

b) 21x-15x+23=112 ; 6x=112-23 ; 6x=89 ; x= 89
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                                                                         6 .
c) (presupun ca ai vrut sa scrii + ). 
20x+35x-32=63 ; 55x=63+32 ; 55x=95 ; x= 95
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                                                                     55 .
d) 51-14x-4x=19 ; -18x=-51+19 ; -18x= -32 ; x= 32/18 ;
e) 45x-27x+71=89 ; 18x+71=89 ; 18x=89-71 ; 18x=18 ; x=1 .
f) 4x/13 + 5/13+36=41 ; 4x/13+5/13=41-36 ; 4x/13+5/13=5 ; 4x/13 = -5/13 + 5 ; Amplificam 5 cu 13 : 4x/13=-5/13 + 65/13  /:13  (Acum am simplificat fiecare element din ecuatie cu 13) ; 4x=-5+65 ; 4x=60 ; x=15.
g) 3x/4 + 2/4 -2=3 ; 3x/4 = -2/4+2+3 ; Acum amplificam 2 si 3 cu 4 :
3x/4= -2/4+2/4+3/4 ; Apoi simplificam fiecare element cu 4 :
3x=-2+2+3; 3x=3 ; x=1.
h) 3x/2 -11/2+12=20 ; 3x/2 = +11/2-12+20 ; Amplificam -12 si 20 cu 2 :
3x/2 = +11/2 - 12/2 + 20/2 si apoi simplificam fiecare element cu 2 :
3x=11-12+20 ; 3x=21 ; x=21/3 ; x=7.

Coroana te rog? Am stat sa scriu ecuatiile astea :D . Daca ai vreo neclaritate sa-mi zici.