8*(1.4х+13,6у)+13(0,8х-0,6у)
Если х=1, а у=1, то 8(1,4*1+13,6*1)+13(0,8*1-0,6*1)=8(1,4+13,6)+13(0,8-0,6)=8*15+13*0,2=120+2,6=122,6
<span>\definecolor{c0}{RGB}{0, 0, 0}
\definecolor{c1}{RGB}{189, 23, 23}
\definecolor{c2}{RGB}{51, 153, 255}
\definecolor{c3}{RGB}{51, 153, 51}
\definecolor{c4}{RGB}{102, 0, 204}
{\color{c0}{\color{c0}{\color{c0}{\color{c0}\frac{{\color{c0}2}}{{\color{c0}x}}} + {\color{c0}\frac{{\color{c0}10}}{{\color{c0}{\color{c0}x} \cdot {\color{c0}\left ({\color{c0}{\color{c0}x} - {\color{c0}2}}\right )}}}}} = {\color{c1}\frac{{\color{c1}{\color{c1}1} + {\color{c1}{\color{c1}2} {\color{c1}x}}}}{{\color{c1}{\color{c1}x} - {\color{c1}2}}}}}, {\color{c0}{\color{c0}{\color{c0}x} \neq {\color{c0}0}}, {\color{c0}{\color{c0}x} \neq {\color{c0}2}}}}</span>
1.Девочки-х
Мальчики-4х
4х+х=55
5х=55
55:5=11(девочек)
11*4=44(мальчиков)
Ответ:11 девочек,44 мальчиков.
+(-7) =-7, -(+9)= -9 , -(-7)= +7.
(14 + 3 * 14) * 6 - 77 = (14 + 42) * 6 - 77 = 56 * 6 - 77 = 336 - 77 = 259 - получилось число.