\[\boxed{\mathbf{1052\ (1051)}.\ Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ 9,88\ :2,6 = 3,8 - 2,06 =\]
\[= 1,74 \cdot 3,5 = 6,09\]
\[9,88\ :3,8 = 98,8\ :38 = 2,6\]
\[3,8 - 1,74 = 2,06\]
\[6,09\ :1,74 = 609\ :174 = 3,5\]
\[Ответ:\ \ a = 2,6;\ \ b = 2,06;\ \ \]
\[c = 3,5.\]
\[2)\ 6,2 \cdot 2,8 = 17,36 + 2,74 =\]
\[= 20,1\ :13,4 = 1,5\]
\[17,36\ :6,2 = 173,6\ :62 = 2,8\]
\[20,1 - 17,36 = 2,74\]
\[20,1\ :1,5 = 201\ :15 = 13,4\]
\[Ответ:\ \ x = 2,8;\ \ y = 2,74;\ \ \]
\[z = 13,4.\]