Question

2x+3y=27
x-y=11
решите методом подстановки

Answer 1

2x+3y=27
x-y=11 

x=(27-3y)/2

x=y+11

1)(27-3y)/2=y+11

27-3y=2y+22

5y=5

y=1

2)x=1+11

x=12

Answer 2

2x+3y=27
x-y=11

 

2(y+11)+3y=27
x=y+11

 

2y+3y=27-22

5y=5

y=1

 

x=12

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