Question

aflati a si b stind ca sunt direct proportionale cu 3 si 4 iar 2a+3b =54​

Answer 1

$\frac{a}{3} = \frac{b}{4} = > a = \frac{3b}{4}$

$2a + 3b = 54$

$2 \times \frac{3b}{4} + 3b = 54$

$\frac{3b}{2} + \frac{6b}{2} = \frac{54 \times 2}{2}$

$9b = 54 \times 2$

$b = \frac{54 \times 2}{9} = 6 \times 2 = 12$

$a = \frac{3b}{4} = \frac{3 \times 12}{4} = 3 \times 3 = 9$