$1)=\frac{\frac{3}{12}+\frac{8}{12}-\frac{6}{12} }{\frac{6}{12}-\frac{3}{12}+\frac{8}{12} } =\frac{\frac{5}{12} }{\frac{11}{12} } =\frac{5}{12}*\frac{12}{11} = \frac{5}{11} \\ \\ 2) =\frac{\frac{27}{45} -\frac{15}{45}-\frac{10}{45} }{\frac{7}{15}+\frac{10}{15}-\frac{12}{15} } =\frac{\frac{2}{45} }{\frac{5}{15} } =\frac{2}{45}*\frac{15}{5} = \frac{2}{15} [tex]\\ \\ 3) =\frac{\frac{16}{60}-\frac{10}{60}-\frac{5}{60} }{\frac{5}{60}+\frac{45}{60} -\frac{24}{60} } =\frac{\frac{1}{60} }{\frac{26}{60} } =\frac{1}{60} *\frac{60}{26} =\frac{1}{26}\\ \\ 4)=\frac{\frac{9}{24} +\frac{6}{24}+\frac{20}{24} }{\frac{12}{24} +\frac{16}{24}-\frac{3}{24} } =\frac{\frac{35}{24} }{\frac{25}{24} } =\frac{35}{24} *\frac{24}{25} =\frac{7}{5} =1\frac{2}{5}$

Пошаговое объяснение:

0 0

4 года назад

Пзя, решите с 3 по 8

Мелена-8 [28]

$\displaystyle\tt 3) \ \ \ \sqrt{\frac{7x+28}{18} } =7 \ |()^2 \\\\{}\ \ \ \ \ \ \ \frac{7x+28}{18}=49 \ | \cdot 18 \\\\{}\ \ \ \ \ \ \ 7x+28=882\\\\{}\ \ \ \ \ \ \ 7x = 882-28\\\\{}\ \ \ \ \ \ \ 7x = 854\\\\{}\ \ \ \ \ \ \ x = 854:7\\\\{}\ \ \ \ \ \ \ x = 122$

$\displaystyle\tt 4) \ \ \ \sqrt{-54-15x} =-x \ |()^2 \\\\{}\ \ \ \ \ \ \ -54-15x=x^2\\\\{}\ \ \ \ \ \ \ x^2+15x+54=0\\\\{}\ \ \ \ \ \ \ D=225-216=9=3^2\\ \\ {}\ \ \ \ \ \ \ x_1=\frac{-15-3}{2} =-9\\ \\ {}\ \ \ \ \ \ \ x_2=\frac{-15+3}{2} =-6$

<u>Меньший корень: х = -9</u>

$\displaystyle\tt 5) \ \ \ \sqrt{6x+57} =9 \ |()^2 \\\\{}\ \ \ \ \ \ \ 6x+57=81\\\\{}\ \ \ \ \ \ \ 6x=81-57\\\\{}\ \ \ \ \ \ \ 6x=24\\\\{}\ \ \ \ \ \ \ x=24:6\\\\{}\ \ \ \ \ \ \ x=4$

$\displaystyle\tt 6) \ \ \ \sqrt[3]{x+2} =4 \ |()^3 \\\\{}\ \ \ \ \ \ \ x+2=64\\\\{}\ \ \ \ \ \ \ x=64-2\\\\{}\ \ \ \ \ \ \ x=62$

$\displaystyle\tt 7) \ \ \ \sqrt{-10+7x} =x \ |()^2 \\\\{}\ \ \ \ \ \ \ -10+7x=x^2\\\\{}\ \ \ \ \ \ \ x^2-7x+10=0\\\\{}\ \ \ \ \ \ \ D=49-40=9=3^2\\ \\ {}\ \ \ \ \ \ \ x_1=\frac{7-3}{2} =2\\ \\ {}\ \ \ \ \ \ \ x_2=\frac{7+3}{2} =5$

<u>Меньший корень: х = 2</u>

$\displaystyle\tt 8) \ \ \ \ (x-7)^9 =-512\\ \\ {}\ \ \ \ \ \ \ (x-7)^9=(-2)^9\\ \\ {}\ \ \ \ \ \ \ x-7=-2\\ \\ {}\ \ \ \ \ \ \ x=-2+7\\ \\ {}\ \ \ \ \ \ \ x=5$

0 0

4 года назад