Question

1.Вычислите. 2.Выполните действия.3.Привести к общему знаменателю дроби:​Те номера которые видны.

Answer 1

$1)\frac{3}{19}+\frac{7}{19}=\frac{1*3+1*7}{19} =\frac{10}{19} \\\\\frac{5}{11}-\frac{7}{9} =\frac{9*5-11*7}{99} =\frac{45-77}{99} =-\frac{32}{99} \\\\1\frac{2}{3} +2\frac{3}{5}=\frac{5}{3} +\frac{13}{5} =\frac{5*5+3*13}{15} =\frac{25+39}{15} =\frac{64}{15} =4\frac{4}{15} \\\\\frac{3}{40}+\frac{1}{10} =\frac{1*3+4*1}{40} =\frac{7}{40} \\\\\frac{7}{24} -\frac{5}{36}=\frac{3*7-2*5}{72} =\frac{21-10}{72} =\frac{11}{72} \\\\2)21x^5y^6*2y^3=42x^5y^{6+3}=42x^5y^9\\3a^4b^5*6a^2b=18a^{4+2}b^{5+1}=18a^6b^6\\(4a^6-b)*ab=4a^{6+1}b-ab^[1+1}=4a^7b-ab^2\\2xy^3(x+y)=2x^{1+1}y^3+2xy^{3+1}=2x^2y^3+2xy^4\\27a^3b^8:(3ab^2)=9a^{3-1}b^{8-2}=9a^2b^6\\(a-3b)(3b+a)=(a-3b)(a+3b)=a^2-9b^2\\|(a-b)(a+b)=a^2-b^2|\\\\\\3)a)\frac{1}{6x^2}u \frac{1}{4x} \\\\HO3=12x^2\\\\\frac{2}{12x^2} u \frac{3x}{12x^2} \\\\b)\frac{1}{3x^2y} u\frac{1}{12xy^2} u\frac{1}{18x^2y^3} \\HO3=36x^2y^3\\\frac{12y^2}{36x^2y^3} u\frac{3xy}{36x^2y^3} u\frac{2}{36x^2y^3}$