Răspuns :
[tex]x- \text {masura \ unghiului} \\ 3x+ \frac{x}{2}=180$^{\circ}$ - x /\times2 \\ 6x+x=360$^{\circ}$ - 2x \\ 6x + x + 2x = 360$^{\circ}$ \\ 9x = 360$^{\circ}$ \\ x = 360$^{\circ}$ : 9 \\ x=40$^{\circ}$ \\ \\ [/tex]
Fie x-masura unghiului
3x+x/2=180-x |×2
=>6x+x=360-2x |+2x
=>9x=360 |:9
=>x=40
3x+x/2=180-x |×2
=>6x+x=360-2x |+2x
=>9x=360 |:9
=>x=40