Часть 1 страница 42, ГДЗ по математике за 4 класс к рабочей тетради Дорофеева
Среднее арифметическое
\[{\def\arraystretch{1.4}\begin{array}{lccccc} \boxed{6;\ 13;\ 8} & 13 & 27 & 3 & \hspace{1.25em}\mathclap{\vcenter{\textcolor{#e03131}{\Huge\bigcirc}}}\mathclap{9}\hspace{1.25em} & 10 \\ \mathrlap{\textcolor{#808080}{(6 + 13 + 8) : 3 = 9}} & & & & & \\[8pt] \boxed{70;\ 20;\ 132;\ 58} & 4 & 24 & 145 & 132 & \hspace{1.25em}\mathclap{\vcenter{\textcolor{#e03131}{\Huge\bigcirc}}}\mathclap{70}\hspace{1.25em} \\ \mathrlap{\textcolor{#808080}{(70 + 20 + 132 + 58) : 4 = 70}} & & & & & \\[8pt] \boxed{120;\ 80;\ 40;\ 60;\ 200} & \hspace{1.25em}\mathclap{\vcenter{\textcolor{#e03131}{\Huge\bigcirc}}}\mathclap{100}\hspace{1.25em} & 140 & 240 & 40 & 200 \\ \mathrlap{\textcolor{#808080}{(120 + 80 + 40 + 60 + 200) : 5 = 100}} & & & & & \\[8pt] \boxed{2;\ 20;\ 200;\ 300;\ 2;\ 220} & 300 & 200 & \hspace{1.25em}\mathclap{\vcenter{\textcolor{#e03131}{\Huge\bigcirc}}}\mathclap{124}\hspace{1.25em} & 222 & 22 \\ \mathrlap{\textcolor{#808080}{(2 + 20 + 200 + 300 + 2 + 220) : 6 = 124}} & & & & & \end{array}}\]
\(AB = \textcolor{#e03131}{\mathbf{6}}\text{ см},\ BC = \textcolor{#e03131}{\mathbf{8}}\text{ см}\)
\(S = 8 \cdot 6 = \textcolor{#e03131}{\mathbf{48}}\text{ (см}^2\text{)}\)
\(P = (8 + 6) \cdot 2 = \textcolor{#e03131}{\mathbf{28}}\text{ (см)}\)

Радиус окружности — \({\textcolor{#e03131}{\mathbf{5}}}\) см.
\[\begin{aligned} 260 \overset{\mathclap{\textcolor{#808080}{\scriptstyle 50}}}{-} 35 \cdot 6 &\mathrel{\hspace{0.72em}\mathclap{\vcenter{\Large\bigcirc}}\mathclap{\textcolor{#e03131}{\pmb{\boldsymbol{>}}}}\hspace{0.72em}} 40 & \quad\kern-1em 900 : 18 \overset{\mathclap{\textcolor{#808080}{\scriptstyle 500}}\rule[-0.35em]{0pt}{0.35em}}{\cdot} 10 &\mathrel{\hspace{0.72em}\mathclap{\vcenter{\Large\bigcirc}}\mathclap{\textcolor{#e03131}{\pmb{\boldsymbol{<}}}}\hspace{0.72em}} 600 & \quad\kern-1em 150 \cdot 4 \overset{\mathclap{\textcolor{#808080}{\scriptstyle 50}}\rule[-0.35em]{0pt}{0.35em}}{:} 12 &\mathrel{\hspace{0.72em}\mathclap{\vcenter{\Large\bigcirc}}\mathclap{\textcolor{#e03131}{\pmb{\boldsymbol{<}}}}\hspace{0.72em}} 70 \\ 788 : 4 \overset{\mathclap{\textcolor{#808080}{\scriptstyle 95}}}{-} 102 &\mathrel{\hspace{0.72em}\mathclap{\vcenter{\Large\bigcirc}}\mathclap{\textcolor{#e03131}{\pmb{\boldsymbol{>}}}}\hspace{0.72em}} 60 & \quad\kern-1em 7 \overset{\mathclap{\textcolor{#808080}{\scriptstyle 140}}\rule[-0.35em]{0pt}{0.35em}}{\cdot} (120 : 6) &\mathrel{\hspace{0.72em}\mathclap{\vcenter{\Large\bigcirc}}\mathclap{\textcolor{#e03131}{\pmb{\boldsymbol{=}}}}\hspace{0.72em}} 140 & \quad\kern-1em 480 : 3 \overset{\mathclap{\textcolor{#808080}{\scriptstyle 70}}}{-} 90 &\mathrel{\hspace{0.72em}\mathclap{\vcenter{\Large\bigcirc}}\mathclap{\textcolor{#e03131}{\pmb{\boldsymbol{<}}}}\hspace{0.72em}} 80 \end{aligned}\]