1)45-5x(B KB)=0
-5x(B KB)=-45
5x(B KB)=45
x(B KB)=9
x=3
3)3x(B KB)+8x-3=0
D=b(B KB)-4ac
D=64+36
D=100
x1.2=-b± <span>√</span> D/2a
x1.2=-8±10/6
x1=-8+10/6=1/3 x2=-8-10/6=-3
х+2=10