232.
1)-9x²+8x+1 =(x+6/7)(x-22/7)
D= (8)²-4×(-9)×1=64-36=28
√D=14>0
x1=-8+14/2×(-9)=-6/7
x2=-8-14/2×(-9)=22/7
2)x²+20x-96=(x-4)(x+24)
D=(20)²-4×1×(-96)=400+384=784
√D=28>0
x1=-20+28/2×1=8/2=4
x2=-20-28/2×1=-48/2=-24
3)-4x²+3x+1=(x+1/4)(x-1)
D=(3)²-4×(-4)×1=9+16=25
√D=5>0
x1=-3+5/2×(-4)=-1/4
x²=-3-5/2×(-4)=1
4)5x²+2x-3=(x-3/5)(x+1)
D=(2)²-4×5×(-3)=4+60=64
√D=8
x1=-2+8/2×5=6/10=3/5
x2=-2-8/2×5=-10/10=-1
5)3x²+4x-7=(x-1)(x+7/3)
D=(4)²-4×3×(-7)=16+84=100
√D=10
x1=-4+10/6=6/6=1
x2=-4-10/6=-7/3
6)-3x²+5x-8=(x+11)(x-38/3)
D=(5)²-4×(-3)×(-8)=25-96=-71
x1=-5+71/2×(-3)=-11
x2=-5-71/2×(-3)=38/3