(aˇ2+2ab)/(a-4b) - (10ab-16bˇ2)/(a-4b)=
=a(a+2b)/(a-4b) - 2b(5a-8b)/(a-4b)=
=(a(a+2b)-2b(5a-8b))/(a-4b)=
=(aˇ2+2ab-10ab+16bˇ2)/(a-4b)=
=(aˇ2-8ab+16bˇ2)/(a-4b)=
=(a-4b)(a-4b)/(a-4b)=a-4b
5y+3=36-y
5y+y=36-3
6y=33
y=5.5
<span>19косинус 5/синус 85=19 cos(90-85)/sin 85=19 sin 85/sin 85=19</span>
Ответ будет: - 0,8. решение во вложении