2. c = 75 - гипотенуза, угол beta = 53° 8', alpha = 90° - 53° 8' = 36° 52'
b = c*sin beta = 75*sin 53° 8'
a = c*sin alpha = 75*sin 36° 52'
3. a = 15; b = 8; c = √(15^2 + 8^2) = √(225+64) = √289 = 17
Углы sin alpha = a/c = 15/17; sin beta = b/c = 8/17.
4. b = 90; угол beta = 58° 7'; alpha = 90° - 58° 7' = 31° 53'
Гипотенуза c = b/sin beta = 90/sin 58° 7'
Катет a = c*sin alpha = 90*sin 31° 53'/sin 58° 7'
1)(a-2)(a+2)/a(2-a)=-(2+a)/a
2)3(x-c)/a(c-x)=-3/a
3)x(x-1)(x+1)/x(1-x)=-(x+1)
4)ax(a-x)/x(x-a)=-a