Question

VA ROG AJUTATIMA VA ROGGGGGGGGGGGGGG

Se dau numerele reale a, b ,  astfel incat  a+3b=7 si 2b-5c=9 . Determinati
a) a+5b-5c

b)a+b+5c

c) 2a+6b

d) 3a+7b+5c

e) 2a+10b-10c

f)2a+15c

Answer 1

trebuie sa sesfaci numerele in asa fel incat sa regasesti ceea ce ti se da
a+3b=7
2b-5c=9
a)a+5b-5c=a+3b+2b-5c=7+9=16
b)a+b+5c=a+3b-2b+5c=a+3b-(2b-5c)=7-9=-2
c) 2a+6b+a+3b+a+3b=7+7=14
d) 3a+7b+5c=3a+9b+2b-5c=7.3+9=30
e) 2a+10b-10c=2a+6b+4b-10c=2.7+2.9=32
f) 2a+15c=2a+6b-6b+15c=2a+6b-(6b-15c)=2.7-9.3=-7