\[\boxed{\text{778\ (778)\ .\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ S = 4t + 5\]
\[2)\]
\[t,\ ч\] | \[0\] | \[0,25\] | \[0,5\] | \[0,75\] | \[1\] | \[1,25\] | \[1,5\] | \[1,75\] | \[2\] |
---|---|---|---|---|---|---|---|---|---|
\[S,\ км\] | \[5\] | \[6\] | \[7\] | \[8\] | \[9\] | \[10\] | \[11\] | \[12\] | \[13\] |
\[\boxed{\text{778.\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ x² - 28x + 200 =\]
\[= x^{2} - 28x + 196 + 4 =\]
\[= (x - 14)^{2} + 4\]
\[принимает\ наименьшее\ \]
\[значение\ при\ x = 14 \Longrightarrow\]
\[\Longrightarrow 0 + 4 = 4\]
\[2)\ 9x² + 30x - 25 =\]
\[= 9x^{2} + 30x + 25 - 50 =\]
\[= (3x + 5)^{2} - 50\]
\[принимает\ нименьшее\ \]
\[значение\ при\ 3x + 5 = 0,\ \]
\[x = - \frac{5}{3} \Longrightarrow\]
\[0 - 50 = - 50\]