c+g=40, g=40-c
[tex]2c- \frac{1}{2}g=60 [/tex]
amplificam 2c si 60 cu 2 ptu a aduce la acelasi numitor
[tex] \frac{4c}{2}- \frac{g}{2}= \frac{120}{2} [/tex]
4c-g=120
il inlocuim pe g
4c-(40-c)=120
4c-40+c=120
4c+c=120+40
5c=160
c=160:5
c=32
32 raspunsuri corecte
32+g=40
g=40-32
g=8
8 raspunsuri gresite