1)-10x^2 +3x+1=0
d=b^2 - 4ac = 3^2 - 4*(-10)*1 = 9+40 = 49
VD = V49 = 9
-b+ - VD
Xo = ----------------
2a
x1 = -3+9/2 *(-10) = 6/-20 = -3/10
x2 = -3-9/2*(-10) = -12/-20 = 3/5
OTBET: x=-3/10 i x=3/5
2) -3x^2 - 2<em>x</em> +8=0
D = b^2 - 4ac = -2^2 -4*(-3)*8= 4+96 = 100
VD = V100 = 10
x1 = 2+10/2*(-3) = 12/-6 = -2
x2 = 2-10/2*(-3) = -8/-6 = 4/3
3) 3x^2+6+11x=0
3x^2+11x+6=0
D = 11^2 - 4*3*6 = 121 - 72 = 49
VD = V49 = 7
x1 = -6+7/2*3 = 1/6
x2 = -6-7/2*3 = -13/6 = -2 1/6
4) 15+17x-4x^2=0
-4x^2+17x+15 = 0
D = 17^2 - 4*(-4)*15 = 289 +240 = 529
VD = V529 = 23
x1 = -17+23/2*(-4) = 6/-8 = -3/4
x2 = -17-23/2*(-4) = -40/-8 = 5
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-369.......................
(√12+√8)^2 /10+√96= (12+2√96+8)/10+√96=(20+12√96)/10=(20+48√6)/10=(10+24√6)/5=2(1+2,4√6)=<span>13,7575507654</span>
(3x+5)(3x-5)-(3x-1)^2=-4
(9x^2-15x+15x-25)-(9x^2-6x+1)=-4
9x^2-25-9x^2+6x-1=-4
-25+6x-1=-4
6x=-4+25+1
6x=22
x=3,8
Ответ:x=3,8.
<span>10х-2(4х-5)=2х+10</span>
<span>Раскрим скобки:</span>
<span>10x-8x+10=2x+10</span>
<span>2x-2x=0</span>
0x=0
х-любое число
Ответ: х-любое
<span>1)(-0.76-0.44):2*2/3=(-1,2)):2*2/3=(-1,2)/3=-0,4</span>
<span>2) <span>(3*5/14-2*3/4)*(-3*5/17)=(15/14-6/4)(-15/17)=((30-42)/28)(-15/17)=(3/7)*(15/17)=45/119</span></span>