10х2 + 3х = 1 3х2 - 1 = 2х (х-2)(х+2)-2х(х-3)=6-х (х+1)2 = 1 - ( 7 +х)х. Created by Nastuha67. algebra-ru

10х2 + 3х = 1 3х2 - 1 = 2х (х-2)(х+2)-2х(х-3)=6-х (х+1)2 = 1

August 2022 1 10 Report

10х2 + 3х = 1
3х2 - 1 = 2х
(х-2)(х+2)-2х(х-3)=6-х
(х+1)2 = 1 - ( 7 +х)х

Answers & Comments

alexooooon 10x^2 + 3x - 1 = 0;
       D = b^2 - 4ac;
D = 3^2 - 4 * 10 * (-1);
D = 9 - -40 = 49;
D > 0, два корня!
       x1,2 = (-b ± √D)/2a;
x1:x = (-3 + 7)/2*10;
     x = 4/20; |:4
     x = 1/5;
x2:x = (-3 - 7)/2*10;
     x = -(10/20); |:10
     x = -(1/2);
       Ответ: 1/5; -(1/2).

3x^2 - 2x - 1 = 0;
       D = b^2 - 4ac;
D = -2^2 - 4 * 3 * (-1);
D = 4 - -12 = 16;
D > 0, два корня!
       x1,2 = (-b ± √D)/2a;
x1:x = (2 + 4)/2*3;
     x = 6/6; |:6
     x = 1
x2:x = (2 - 4)/2*3;
     x = -(2/6); |:2
     x = -(1/3);
       Ответ: 1; -(1/3).

-1x^2 + 7x - 10 = 0;
       D = b^2 - 4ac;
D = 7^2 - 4 * (-1) * (-10);
D = 49 - 40 = 9;
D > 0, два корня!
       x1,2 = (-b ± √D)/2a;
x1:x = (-7 + 3)/2*(-1);
     x = -(4/2); |:-2
     x = 2;
x2:x = (-7 - 3)/2*(-1);
     x = -(10/2); |:-2
     x = 5;
       Ответ: 2; 5.

В последнем, похоже что нужно было -х(7+х)
2x^2+9x=0
x(2x+9)=0
[x = 0 [x = 0
[2x = -9 [x = -4(1/2)

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