Răspunsuri

2014-10-11T09:44:14+03:00
Ab+ac=420
b+c=14
ab+ac=420
a*(b+c)=420
14a=420
a=30 
(am dat factor comun pe a)
2014-10-11T09:46:29+03:00
AB+AC=420
B+C=14
=> A(B+C)=420
=>A * 14=420
=>A=420 : 14
=>A=30