..................................
1.
1,17х=20,75
х= 20,75/1,17≈17,735
2.
1,27х=31,75
х=31,75/1,27 = 25
а)х² + 3х - 10 =
0
D=b²-4ac=9-4*1*(-10)=49
<span>X=-b±√D/2a=3±√49/2
</span>
X=3+7/2=5
<span>X=3-7/2=-2
б)</span><span> 2х² - 5х +2 = 0
D=25-4*2*2=9
X=5</span>±3/4
X=5+3/4=2
X=5-3/4=1/2
<span>в)<span>2х - (х + 1)² =
3х² - 5
2x-x²+2x+1=3x<span>²-5
</span>2x-x²+2x+1-3x<span>²+5=0
</span>4x²-4x<span>-6=0
</span>D<span>=16-4*4*(-6)=112
</span>X=4±</span>√<span>112/8
</span></span>г) (3х - 1) (х
- 9) = (х + 3)²
3x²-27x-x+9=x²+6x+9
3x²-27x-x+9-x²-6x-9=0
2x²-34x=0 /2
x²-17=0
D=289-4*1*0=289
<span>X=17±√289 /2
</span>
X=17+17 /2=17
X=17-17 /2=0
<span>
</span>На счёт в,г не очень уверена!!