1)(y+2)(3y-9)=0
a)y+2=0, y=-2
b)(3y-9)=0, y=3
16-zˇ2=0,(4+z)(4-z)=0
a)4+z=0, z=-4
b)4-z=0, z=4
xˇ2-8x+16=0, (x-4)ˇ2=0, x1,2= 4
tˇ5=9tˇ3,tˇ5-9tˇ3=tˇ3(tˇ2-9)=tˇ3(t+3)(t-3)=0
t1=t2=t3=0,t4=-3,t5=3
2)b(b+4)=2bˇ2-32, bˇ2+4b=2bˇ2-32
bˇ2-4b-32=0, D=16+128=144, V(D)=V(144)=12
b1=(4+12)/2=8
b2=(4-12)/2=-4