Question

ПРОПОРЦИЯ СРОЧНО 15 БАЛЛОВ
5,6 0,4
____ = ____
3x+12 3

Answer 1

0.4(3х+12)=5.6*3

1.2х+4.8=16.8

1.2х=16.8-4.8

1.2х=12

х=12:1.2

х=10

Answer 2

$\frac{ \frac{28}{5} }{3x + 12} = \frac{ \frac{2}{5} }{3} \\ \\ \frac{28}{5(3x + 12)} = \frac{2}{15} \\ \\ 420 = 10(3x + 12) \\ 42 = 3x + 12 \\ - 3x = 12 - 42 \\ - 3x = - 30 \\ x = 10$