Question

Determina numerele a si b, stiind ca a=3b si media lor aritmetica este egala cu 84
Ajutor!
Dau coronita (dar cum?)

Answer 1

ma=a+b/2

ma=3b+b/2

4b/2=84

4b=168

b=42

a=3*42

a=126

Answer 2

$a = 3b \\ \frac{a + b}{2} = 84 \\ rezulta \: ca \: a + b = 84 \times 2 \\ a + b = 168 \\ daca \: a = 3b \: rezulta \: 3b + b = 168 \\ 4b = 168 \\ b = \frac{168}{4} \\ b = 42 \\ a = 3b \\ a = 3 \times 42 \\ a = 126 \\ \\ verificare \\ \frac{a + b}{2} = 84 \\ \frac{126 + 42}{2} = 84 \\ \frac{168}{2} = 84 \\ 84 = 84$