Ctg 60 = 3.12 ctg60^2 = 9.759
0,10246556747070714357147424179579
25c¹⁰=(5c⁵)²;
2) (3⁹x⁹*9³x¹²):(3⁵x¹⁵*27³x³*x)=75;
3⁹*3⁶*x²¹:(3⁵3⁹x¹⁹)=75;
3¹⁵x²:3¹⁴=75;
x²=25;
x=5; x=-5;
{7x+9y=15 //*5
{8x-5y=4 //*9
{35x+45y=75
+
{72x-45y=36
107x=111
x=111/107=1.03
5y=8*1.03-4
y=4.299/5=0.859
x=1.03
y=0.859