In the UK, there are selective secondary schools where admission is based on tests that are called the 11+ tests because they are taken by pupils after their 11th birthday and before their 12th. These tests are highly competitive so there are a number of outfits offering courses to prepare pupils to perform well at these tests.
3 + 11 + 11 + 11 + 12 + 13 + 15 + 15 + 16 + 17 + 19 = 143
12
40
Expand z plus 11 times z plus 11 = (z+11)(z+11) = z2 + 22z + 121.
11 + 4x
11
8+11= 8+11
10 plus 1 is 11.
11 + 110 + 1100 = 1221
-25
-2x + 11 + 6x = 4x + 11
11 + (-5) + (-12) + (-2) =11 - 5 - 12 - 2 =11 - 19 = -8