Question

Помогите решить с 5 по 8,какое сможете)))

Answer 1

$5) (-x^{n-3})^{7}*(x^{5})^{4-n}=-x^{7*(n-3)}*x^{5*(4-n)}=-x^{7n-21}*x^{20-5n}=$
$=-x^{7n-21+20-5n}=-x^{2n-1}$
Ответ: 1

$6)147 frac{11}{14}-144 frac{5}{49}+1 frac{31}{98}=147 frac{77}{98}-144 frac{10}{98}+1 frac{31}{98}=3 frac{67}{98} +1 frac{31}{98}=4 frac{98}{98} =5$
Ответ: 5

$7) frac{6}{x}+ frac{15}{2x} =4$ ОДЗ: х не равно 0
$frac{12}{2x}+ frac{15}{2x}=4$
$frac{27}{2x}=4$
$2x= frac{27}{4}$
$x=frac{27}{8}$
$x=3 frac{3}{8}$
$x=3,375$
Ответ: 3,375

$8) frac{9^{5}*27^{3}}{81^{4}} = frac{(3^{2})^{5}*(3^{3})^{3}}{(3^{4})^{4}}= frac{3^{2*5}*3^{3*3}}{3^{4*4}}= frac{3^{10}*3^{9}}{3^{16}}= frac{3^{10+9}}{3^{16}} = frac{3^{19}}{3^{16}}=3^{19-16}=$
$=3^3=27$
Ответ: 27

Answer 2

1)(-x∧n-2)⁷*(x⁵)∧4-n=-x∧7n-21*x∧20-5n=-x∧2+2n-1=-x∧2n+1
Ответ:5
2)$147 frac{11}{14} -144 frac{5}{49} +1 frac{31}{98} =147 frac{77}{98} -144 frac{10}{98} +1 frac{31}{98} =4 frac{98}{98} =5$
3)
$frac{12+15}{2x} =4$
8x=27
x=3,375
4)$frac{9 ^{5} *27 ^{3} }{81 ^{4} } = frac{(3 ^{2}) ^{5} *(3 ^{3}) ^{3} }{(3 ^{4}) ^{4} } = frac{3 ^{10}*3 ^{9} }{3 ^{16} } = frac{3 ^{19} }{3 ^{16} } =27$