3sqrt(x+2)=2x-5
9x+18=4x^2+25-20x
4x^2-29x+7=0
x=(29+-27)/8
x1=1/4
x2=7
sin720=0
cos240=cos(270-30)=-sin30=-0.5
tg135=tg(90+45)=-ctg45=-1
ctg315=ctg(360-45)=-ctg45=-1
0-0.5-1-1=-2.5