\[\boxed{\mathbf{Страница\ 36.\ }\mathbf{Еуроки\ - \ ДЗ\ без\ мороки}}\]
\[\boxed{\mathbf{3.\ }}\]
\[a - (b + 3) = a - b + 3 \Longrightarrow\]
\[\Longrightarrow неверно\]
\[(40 + x) - y = 40 + (x - y) \Longrightarrow\]
\[\Longrightarrow верно\]
\[(c + b) - a = (c - a) - b \Longrightarrow\]
\[\Longrightarrow неверно\]
\[a - x - y = a - (x + y) \Longrightarrow\]
\[\Longrightarrow верно\]
\[\boxed{\mathbf{4.\ }}\]
\[48 - (17 + a) = 48 - 17 - a =\]
\[= 31 - a\]
\[a - 34 - 22 = a - (34 + 22) =\]
\[= a - 56\]
\[116 - (16 + x) =\]
\[= 116 - 16 - x = 100 - x\]
\[387 - (98 + a) =\]
\[= 387 - 98 - a = 289 - a\]
\[a - 486 - 114 =\]
\[= a - (486 + 114) = a - 600\]
\[b - 77 - 123 =\]
\[= b - (77 + 123) = b - 200\]
\[\boxed{\mathbf{5.\ }}\]
\[52 + x + 33 = x + 52 + 33 =\]
\[= x + (52 + 33) = x + 85\]
\[86 + x + 14 = x + 86 + 14 =\]
\[= x + (86 + 14) = x + 100\]
\[74 + a + 13 = a + 74 + 13 =\]
\[= a + (74 + 13) = a + 87\]
\[c + 82 + 14 = c + (82 + 14) =\]
\[= c + 96\]
\[41 + 28 + a = a + (41 + 28) =\]
\[= a + 69\]
\[\boxed{\mathbf{6.\ }}\]
\[(385 + a) - 213 =\]
\[= (385 - 213) + a =\]
\[= 172 + a\]
\[x - 43 + 50 = (x + 50) - 43 =\]
\[= x + (50 - 43) = x + 7\]
\[(318 + x) - 209 =\]
\[= (318 - 209) + x =\]
\[= 109 + x\]
\[(436 + y) - 186 =\]
\[= (436 - 186) + y =\]
\[= 250 + y\]
\[x - 187 + 379 =\]
\[= (x + 379) - 187 =\]
\[= x + (379 - 187) = x + 192\]
\[a - 426 + 550 =\]
\[= a + (550 - 426) = a + 124\]