👤
a fost răspuns

daca 2 x a + b egal 5 si 2 x b + 3 x c egal 7 calculati 4 x a +8 x b + 9 x c.

Răspuns :

Didi12342
2×a + b = 5 |×2
2×b + 3×c = 7 |×2

4×a + 2×b = 10
4×b + 6×c = 14

4×a + 8×b + 9×c =
= (4×a+2×b)+(4×b+6×c) + (2×b + 3×c) =
= 10 + 14 + 7 =
= 31

Alte intrebari