39x³y/26x²y²=3x/2y
5y/(y²-2y)=5y/y(y-2)=5/(y-2)
cos (pi/12)=cos(pi/3-pi/4)=cos (pi/3)cos (pi/4)+sin(pi/3)sin(pi/4)=1/2*|/2/2+|/3/2*|/2/2=|/2/4+|/6/4=(|/2+|/6)/4
|/ Корень
/ дробь
=12√2cos225=12√2cos(180+45)=12√2(-cos45)= -12√2 *<span>√2/2= -12</span>
3) 0,2x + 1x = 1,4 - 2,7
1,2x = -1,3
x= 13/12
4) -1,5x - 0,3x = -3,6 - 5,4
-1,8x = - 9
x = 5