Question

Уравнение у:4.2=3.4:5.1

Answer 1

$\frac{y}{4.2} = \frac{3.4}{5.1} \\ \\ y= \frac{4.2*3.4}{5.1} \\ \\ y= \frac{14.28}{5.1} \\ \\ y=2.8$

Answer 2

5,1у=3,4*4,2
5,1у=14,28
у=14,28:5,1
у=2,8