\[\boxed{\mathbf{141.}}\]
\[\textbf{а)}\ 135 - 5 = 130\]
\[240 + 6 = 246\]
\[352 - 1 = 351\]
\[404 - 12\ :3 = 404 - 4 = 400\]
\[573 - 18\ :6 = 573 - 3 = 570\]
\[200 + 24\ :4 = 200 + 6 = 206\]
\[\textbf{б)}\ 430 + 48\ :6 = 430 + 8 = 438\]
\[505 - 45\ :9 = 505 - 5 = 500\]
\[999 - 54\ :6 = 999 - 9 = 990\]