Решение
1) (a + 3)/(a - 1) + (a + 5)/(2 - 2a) = <span>(a + 3)/(a - 1) - (a + 5)/[2*(a - 1)] =
(2a + 6 - a - 5) / </span>[2*(a - 1)] = (a + 1) / [2*(a - 1)]<span>
2) (2x - y) /(2x + y) + y/(4x + 2y) = </span><span> (2x - y) /(2x + y) + y / ]2*(2x + y)] =
(4x - 2y + y) / </span>]2*(2x + y)] = = (4x - y) / <span>]2*(2x + y)] </span>
100*100\20=500 это пропорция
1)cos(5π/2+x)=-1
cos(2π+π/2+x)=-1
cos(π/2+x)=-1
sinx=-1
x=-π/2+2πn
2)sin(9π/2+x)=-1
sin(4π+π/2+x)=-1
sin(π/2+x)=-1
cosx=-1
x=π+2ππn