Question

5y+7(3-y)=3(5-2y)-6-это первый. 7y-4(3y+5)=2-3(4y-9)

Answer 1

5y+7(3-y)=3(5-2y)-6

5y+21-7y=15-6y-6

5y-7y+6y=15-6-21

4y= -12

y=-12:4

у= - 3

 

 

7у-4(3у+5)=2-3(4у-9)

7у-12у-20=2-12у+27 

 7у-12у+12у=20+2+27

7у= 49

у=49:7

у=7 

 

 

Answer 2

$5y+7(3-y)=3(5-2y)-6$

 

$5y+21-7y=15-6y-6$

 

$21-2y=9-6y$

 

$6y-2y=9-21$

 

$4y=-12$

 

$y=-12:4$

 

$y=-3$

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$5cdot(-3)+7cdot(3-(-3))=3cdot(5-2cdot(-3))-6$ (это проверка)

 

$-15+7cdot(3+3)=3(5+6)-6$

 

$-15+7cdot6=3cdot11-6$

 

$-15+42=33-6$

 

$27=27$

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$7y-4(3y+5)=2-3(4y-9)$

 

$7y-12y-20=2-12y+27$

 

$-5y-20=29-12y$

 

$12y-5y=29+20$

 

$7y=49$

 

$y=49:7$

 

$y=7$

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$7cdot7-4cdot(3cdot7+5)=2-3cdot(4cdot7-9)$

 

$49-4cdot(21+5)=2-3cdot(28-9)$

 

$49-4cdot26=2-3cdot19$

 

$49-104=2-57$

 

$-55=-55$