Question

Numerele naturale a si b sunt direct proportionale cu 2 si 5.Daca 3a+b=44,atunci calculati valoarea nr.5a-b.

Answer 1

a=2k
b=5k

3a+b=44
3*2k+5k=44
6k+5k=44
11k=44
k=44:11
k=4

a=2*4
a=8

b=5*4
b=20

Deci 5a-b=
5*8-20=
40-20=20

Answer 2

apoi fractia o notez cu    /

a/2=b/5=k
a/2=k⇒a=2k
b/5=k⇒b=5k
inlocuim in formula
3×2k+5k=44
11k=44
k=44:11
k=4
2k=2×4=8, a=8
5k=5×4=20, b=20
si valoarea
5×8-20=20