Răspunsuri

2014-10-25T17:53:48+03:00
Cel mai inteligent răspuns!
2014-10-25T18:17:44+03:00
A)8(2x+3)-4(5x+1)=6(-x+5)-2
16x+24-20x-4=-6x+30-2
-4x+20=-6x+28
-4x+6x=28-20
2x=8
x=4
b)2*[3(2x-5)+x-3]+16=18+3[2(5x-4)+3(x+4)]
2(6x-15+x-3)+16=18+3(10x-8+3x+12)
12x-30+2x-6+16=18+30x-24+9x+36
12x+2x-30x-9x=18-24+36+30+6-16
-25x=50
x=-2
c)9-7·[3(2x-1)+2(x+5)]=5·[2·(4x-5)-3(x-2)]-x
9-7(6x-3+2x+10)=5(8x-10-3x+6)-x
9-42x+21-14x-70=40x-50-15x+30-x
-42x-14x-40x+15x+x=-50+30+70-21-9
-80x=20
x=-1/4
spune-mi si mie cand se schimba semnul din - in +
cand in fata parantezei ai semnul - (atunci toate semnele din paranteze se schimba...de exemplu, daca ai -2(2x+4)=-4x-8
nu stiu cum as putea sa-ti explic mai bine...din pacate
m-am descurcat ms mult
ii bine atunci...ma bucur :)