Question

помогите пожалуйста
нужно очень срочно.
До отправки осталось 10 минут
даю 12 баллов ​

Answer 1

1.1)

$\dfrac{3a+5}{4} = \dfrac{5a+1}{3}\\\\(3a + 5)\cdot3 = (5a+1)\cdot4\\\\9a+15 = 20a+4\\\\20a-9a=15-4\\\\11a = 11\\\\a = 1$

1.2)

$\dfrac{5m+3}{5}=\dfrac{m-5}{8}\\\\(5m+3)\cdot8 = (m-5)\cdot5\\\\40m+24 = 5m-25\\\\40m-5m=-25-24\\\\35m=-49\\\\m = -\dfrac{49}{35} = -\dfrac{7}{5} = -1\dfrac{2}{5}$

2.1)

$\dfrac{7y}{6}-\dfrac{5y}{18}=\dfrac{4}{27}\\\\\dfrac{9\cdot7y}{9\cdot6}-\dfrac{3\cdot5y}{3\cdot18}=\dfrac{4\cdot2}{27\cdot2}\\\\\dfrac{63y}{54}-\dfrac{15y}{54}=\dfrac{8}{54}\\\\63y-15y=8\\\\48y = 8\\\\y = \dfrac{8}{48} = \dfrac{1}{6}$

2.2)

$\dfrac{2b}{7} + \dfrac{b}{4} = \dfrac{15}{14}\\\\\dfrac{4\cdot2b}{4\cdot7} + \dfrac{7\cdot b}{7\cdot4} = \dfrac{2\cdot15}{2\cdot14}\\\\\dfrac{8b}{28} + \dfrac{7b}{28} = \dfrac{30}{28}\\\\8b + 7b = 30\\\\15b = 30\\\\b = 2$

2.3)

$-\dfrac{x}{8} + 1 = \dfrac{x}{12}\\\\-\dfrac{3\cdot x}{3\cdot8} + \dfrac{24\cdot1}{24\cdot1} = \dfrac{2\cdot x}{2\cdot12}\\\\-\dfrac{3x}{24} + \dfrac{24}{24} = \dfrac{2x}{24}\\\\-3x + 24 = 2x\\\\2x+3x = 24\\\\5x = 24\\\\x = \dfrac{24}{5} = 4\dfrac{4}{5} = 4.8$