Răspuns :
[tex]f+b=23 \\
2(b+4)=f \\
f=2b+8 \\
Inlocuim: \\
2b+8+b=23 \\
3b=15 \\
\underline{b=5} \\
f=2*5+8 \\
\underline{f=18} \\ \\
f|^{\underline{~~~~~~~~~~~~~~~~~~~~~~~~~~~~}}| \\
b.|^{\underline{~~~~~~~}}|^{\underline{~~4~~}}|^{\underline{~~~~~~~}}|^{\underline{~~4~~}}}|[/tex]
f. |----|----|
b. |----|-| |-|=4
1)23+4 = 27
2) (27:3)-4=5
3) 9x2=18
18+5=23 :)
b. |----|-| |-|=4
1)23+4 = 27
2) (27:3)-4=5
3) 9x2=18
18+5=23 :)