1. (-a+2)^2=(2-a)^2= 4-4a+a^2
2. (-b-3)^2=b^2+6b+9
3. (-n+4)^2=(4-n)^2=16-8n+n^2
4. (-x-10)^2= x^2+20x+100
5. (-2x-3y)= 4x^2+12xy+9y^2
-2.5 Я округлил, а так −2.5571428571
4а =10+3/12=13/12
4б=21-20/24=1/24
4г=5-6/7=29/7
6а=2-8=-6
6б=-4/7+12/5=64/35
6в=5/3-3×1/2=5/3-3/2=1/6