32 - 30 + 28 - 26 + ... + 4 - 2
= (32 - 30) + (28 - 26)+ ( 24 - 22) + ( 20 - 18 ) + (16 - 14) + ( 12 - 10) + ( 8 - 6) + (4 - 2)
= 2 + 2 + 2 + 2 + 2 + 2 + 2 +2
=16
32 - 30 + 28 - 26 + ... + 4 - 2
= (32 - 30) + (28 - 26) + (25 - 23) + ... + (8 - 6) + (4 - 2)
= 2 + 2 + 2 + ... + 2 + 2
= 2 . 8 = 16
\(\left(32-30\right)+\left(28-26\right)+...+\left(4-2\right)\)
\(\Rightarrow2+2+...+2\)
\(\Rightarrow2\times16=32\)