Ответ:
43,5''-39,5'' = 4
1,82''+0,72+0,2''= 1,84''+0,72" = 2,04" + 0,52" = 2,56"
z+6.1=22,5
z=22.5-6.1
z=16.4
1 + tg10tg55 / tg55 - tg10=1/tg(55-10)=ctg45=1........................................
x²-xy-2y²=0