Х²-7х+10=0
d=49-4*1*10=9
x1=(7+3)/2=5
x2=(7-3)/2=2
x1=5 x2=2
y1=25-35+10=0 y2=4-14+10=0
X + y = 63
x - y = 19
------------------ +
2x = 82
x = 41
y = 63 - x = 63 - 41 = 22
Ответ
41; 22
Sin x * sin y = 1/2 (cos (x-y) - cos(x+y))
cos (x-y) - cos(x+y) = sqrt(3)/2
cosx * cosy = 1/2 (cos (x-y) + cos(x+y))
cos (x-y) + cos(x+y) = sqrt(3)/2
2 * cos(x-y) = sqrt(3)
cos(x-y) = sqrt(3)/2
x-y = +- (pi/6) + 2pi * k
справишься дальше?
sin (arccos (-12/13)) решить.