A)(6a-b)^2=36a^2-12ab+b^2
b)-(a-b)^2=-a^2-2ab-b^2
v)(a-b)^2+4=a^2-2ab+b^2+4
g)(a+4)^2=a^2+8a+16
d)-(a-b)^2-5=-a^2+2ab-b^2-5
Вс=13²-12²=169-144=25, √25=5
S=12+13+5=30 см²
R=S/ac*вс*4
R=30/(12+5)=30/17=1,7*4=7,05 см
4,526+12(1/5)-(4(2/3)*1,8-4,526)=4,526+12,2-((14/3)*(9/5)+4,526=
=16,726-(8,4+4,526)=16,726-12,926=3,8.