\[\boxed{\mathbf{Стр.\ 33.\ }еуроки - ответы\ на\ пятёрку}\]
\[\boxed{\mathbf{13.}}\]
\[Периметр\ прямоугольника:\]
\[2 \cdot (a + b).\]
\[Площадь\ прямоугольника:\]
\[a \cdot b.\]
\[Длина\] | \[7\ см\] | \[9\ см\] | \[7\ см\] | \[8\ см\] | \[9\ см\] | \[8\ см\] | \[6\ см\] |
---|---|---|---|---|---|---|---|
\[Ширина\] | \[6\ см\] | \[6\ см\] | \[5\ см\] | \[4\ см\] | \[5\ см\] | \[5\ см\] | \[3\ см\] |
\[Периметр\] | \[26\ см\] | \[30\ см\] | \[24\ см\] | \[24\ см\] | \[28\ см\] | \[26\ см\] | \[18\ см\] |
\[Площадь\] | \[42\ см^{2}\] | \[54\ см^{2}\] | \[35\ см^{2}\] | \[32\ см^{2}\] | \[45\ см^{2}\] | \[40\ см^{2}\] | \[18\ см^{2}\] |
\[\boxed{\mathbf{14.}}\]
\[1)\ x \cdot 4 = 56\]
\[x = 56\ :4\]
\[x = 14.\]
\[Проверка:\]
\[14 \cdot 4 = 56\]
\[56 = 56.\]
\[2)\ 51\ :y = 3\]
\[y = 51\ :3\]
\[y = 17.\]
\[Проверка:\]
\[51\ :17 = 3\]
\[3 = 3.\]
\[3)\ x - 19 = 6 \cdot 7\]
\[x - 19 = 42\]
\[x = 42 + 19\]
\[x = 61.\]
\[Проверка:\]
\[61 - 19 = 6 \cdot 7\]
\[42 = 42.\]
\[\boxed{\mathbf{15.}}\]
\[\boxed{\mathbf{16.}}\]
\[Самое\ большое\ трехзначное\ \]
\[число:\ \ \ 999.\]
\[Самое\ маленькое\ трехзначное\ \]
\[число:\ \ 100.\]
\[\boxed{\mathbf{17.}}\]
\[(42\ :3\ :7)\ :2 = 14\ :7\ :2 =\]
\[= 2\ :2 = 1\]
\[(72 - 72)\ :3 = 0\ :3 = 0\]
\[(81 - 9 \cdot 9) \cdot 6 = (81 - 81) \cdot 6 =\]
\[= 0 \cdot 6 = 0\]
\[54\ :9 \cdot (17 - 17) = 6 \cdot 0 = 0\]