Răspuns :
Prima varianta : cu paranteze
(x-5)/5 = 1/2
2(x-5) = 5
2x-10 = 5
2x = 15
x= 15/2
(x-3)/5 < 3
x-3 < 15
x < 12
A doua varianta: fara paranteze
x-5/5 = 1/2
x-1 = 1/2
x = (1+2)/2
x = 3/2
x-3/5 < 3
x < (15+3)/5
x < 18/5
(x-5)/5 = 1/2
2(x-5) = 5
2x-10 = 5
2x = 15
x= 15/2
(x-3)/5 < 3
x-3 < 15
x < 12
A doua varianta: fara paranteze
x-5/5 = 1/2
x-1 = 1/2
x = (1+2)/2
x = 3/2
x-3/5 < 3
x < (15+3)/5
x < 18/5
a.
[tex]x- \frac{5}{5}=\frac{1}{2}[/tex]
[tex]x-1=\frac{1}{2}[/tex]
[tex]x=\frac{1}{2}+1[/tex]
[tex]x=\frac{1+2}{2}[/tex]
[tex]x=\frac{3}{2}~~\in~ Q+[/tex]
b.
[tex]x- \frac{3}{5} \ \textless \ 3[/tex]
[tex]x<3+\frac{3}{5}[/tex]
[tex]x\ \textless \ \frac{15+3}{5} [/tex]
[tex]x\ \textless \ \frac{18}{5} ~~~ \in N* [/tex]
[tex]x- \frac{5}{5}=\frac{1}{2}[/tex]
[tex]x-1=\frac{1}{2}[/tex]
[tex]x=\frac{1}{2}+1[/tex]
[tex]x=\frac{1+2}{2}[/tex]
[tex]x=\frac{3}{2}~~\in~ Q+[/tex]
b.
[tex]x- \frac{3}{5} \ \textless \ 3[/tex]
[tex]x<3+\frac{3}{5}[/tex]
[tex]x\ \textless \ \frac{15+3}{5} [/tex]
[tex]x\ \textless \ \frac{18}{5} ~~~ \in N* [/tex]