Question

Rezolvati in Q+ ecuatia :
a) 2 pe 3 * (1+ 3-7x supra 2 ) =x
b) [ 1,(3)x supra 2 - 9 pe 4 ] : 0,6 = x pe 9

Answer 1

a) 2/3[1+ (3-7x)/ 2 ]=x
2/3+2(3-7x)/4=x
(3-7x)/2=x-2/3
(3-7x)/2=(3x-2)/3
3(3-7x)=2(3x-2)
9-21x=6x-4
-21x-6x=-4-9       
-27x=-13   inmultim -1
27x=13
x=13/27
x=0,(481)

b) [ 1,(3)x/2 - 9/4 ] : 0,6 = x/9
{[(13-1)/9]x/2-9/4}:6/10=x/9
[12x/18-9/4]:3/5=x/9
(2x/3-9/4)·5/3=x/9
[(2x·4-9·3)/12]·5/3=x/9
(8x-27)/12·5/3=x/9
15(8x-27)/36=x/9
(120x-135)/36=x/9
9(120x-135)=36x                  :9
120x-135=4x
120x-4x=135
116x=135
x=135/116