Question

решить систему уравнений методом подстановки: х+5у=35,
3х+2у=27;

Answer 1

х+5у=35,
3х+2у=27

 

x=35-5y

3(35-5y)+2y=27

 

-15y+2y=27-105

-13y=-78

y=6

 

x=35-5*6=35-30=5

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Answer 2

3*(35-5y)+2y=27
105-15y+2y=27
-13y=27-105

-13y=-78

y=6

x= 35-30 

x=5