Question

1) Aflati 2 nr. care au raportul 0,2 si suma 12 .
2) Aflati a si b daca a supra b = 3 supra 7 si 2a + 5b = 82

Answer 1

a)
a/b=0,2 = 2/10=1/5   a=b/5   b=5a
a+b=12
a+5a=12
6a=12
a=2
b=10

b)   a/b=3/7
7a=3b    b=7a/3
2a+5b=82
2a+5×7a/3=82
6a+35a=246
41a=246
a=6
b=7x6/3=14