<span>Cos^{2}30/Sin^{4}45
сos30=</span>√3/2
sin45=√2/2
3/4 : 4/16=3/4*4=3
a²+b² = (a-b)(a+b)
(a+b)² = a²+2ab+b²
(x+9)(x-9) / x²+18x+81 = x²-81 / (x+9)²
x=81
81²-81 / (81+9)² = 81²-81 / 90² = 81(81-1) / 8100 = 80/100 = 0.8
202/2=101(за 1 год)
5000-100
101-x
х=101*100/5000=2,02