Question

determinati numarul necunoscut in fiecare proporti
a) x-2/5=2x-1/13
b) 2x+3/x+5=7/4
c) 4x-5/3=2x+8/2
d) 3x+11/9=x+6/4
e) 4/9=3x+1/2x+12
f) 3/5x+2=7/2x+15

Answer 1

a)2x-x=1/13-2/5
x=1/13-2/5
 aducem la acelasi numitor termenii din dreapta ( n.c=65)
x=5/65-26/65
x=-21/65
b)4(2x+3)=7(x+5)
8x+12=7x+35
8x-7x=35-12
x=23
c)4x-2x=5/3+4/1
2x=5/3+12/3
2x=17/3
x=17/6
d)3x-x=3/2-11/9
2x=27/9-22/9
2x=5/9
x=5/18
e)3x+1/2x=4/9-12
54x+9x=8-216
63x=-208
x=-208/63
f)3/5x-7/2x=15-2
6/10x-35/10x=13
-29x=130
x=/130/29