Question

У:8,4=2,1 решить уравнение

Answer 1

:0
1)8,4 переносим вправо с обратным знаком
2)у=2,1*8,4
   у=17,64

Answer 2

It seems like you've provided an equation: "У:8,4=2,1." However, I'm not sure what the notation "У:" stands for, and the equation itself doesn't look standard. To help you solve the equation, I need more information about what the equation represents and what you're trying to find. Please provide additional context or clarify the equation, and I'll be happy to assist you in solving it.