Question

помогите пожалуйста ​

Answer 1

ОТВЕТ

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5х+ $\frac{7x-12}{3}$ =3х=39

22х-12=3х=39

22х-3х=39=12

19х=51

х= $\frac{51}{19}$

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Правильный ответ: х= $\frac{51}{19}$

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Желаю удачи.

Answer 2

Ответ:

$5x+\frac{7x-12}{3}=x+13 |*3\\\\3*5x+\frac{3(7x-12)}{3} =3x+3*13\\\\15x+7x-12=3x+39\\\\15x+7x-3x= 39+12\\\\19x=51\\\\x=\frac{51}{19}\\\\x= 2\frac{13}{19}$

Проверка:

$5*\frac{51}{19}+\frac{7*\frac{51}{19}-12 }{3}=\frac{51}{19}+13\\\\\frac{225}{19}+\frac{\frac{357}{19}-\frac{12}{1} }{3} =\frac{51}{19}+\frac{13}{1}\\\\\frac{225}{19} +\frac{\frac{357}{19}-\frac{228}{19} }{3}=\frac{51}{19}+\frac{247}{19}\\\\\frac{225}{19}+\frac{\frac{129}{19} }{3}=\frac{298}{19}\\\\\frac{225}{19}+\frac{129}{19}:3=\frac{298}{19}\\\\ \frac{225}{19}+\frac{129}{19}*\frac{1}{3} =\frac{298}{19}\\\\ \frac{225}{19}+\frac{129}{57}=\frac{298}{19}$

$\frac{225}{19}-\frac{298}{19}+\frac{129}{57}=0\\\\\frac{129}{57} -\frac{43}{19} =0\\\\\frac{129}{57} -\frac{129}{57} =0\\\\0=0$