1.
2.
у=(8 8/11+5 4/11) -11 2/11=8 · 11 + 8/11+5 · 11 + 4/11=96/11+59/11=96 + 59/11=155/11
=14 1/11-11 2/11=14 · 11 + 1/11−11 · 11 + 2/11=155/11−123/11=155 − 123/11=32/11=2 10/11
3.
S=a×b=3 ½×3 ½=7/2×7/2=14/4=7/2=3 ½
