\[\boxed{\text{770\ (770).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ 5cx + c^{2} = c(5x + c)\ \]
\[если\ x = 0,17;\ \ c = 1,15:\]
\[1,15 \cdot (5 \cdot 0,17 + 1,15) =\]
\[= 1,15 \cdot (0,85 + 1,15) =\]
\[= 1,15 \cdot 2 = 2,3.\]
\[\textbf{б)}\ 4a^{2} - ab = a \cdot (4a - b)\]
\[если\ \ \ a = 1,47;\ \ b = 5,78:\ \]
\[1,47 \cdot (4 \cdot 1,47 - 5,78) =\]
\[= 1,47 \cdot (5,88 - 5,78) =\]
\[= 1,47 \cdot 0,1 = 0,147.\]