2x^2 + 3x + 4 = 0;
D = b^2 - 4ac;
D = 3^2 - 4 * 2 * 4;
D = 9 - 32 = -23;
D < 0, корней нет!
Ответ: x ∈ Ø.
9x^2 - 6x + 1 = 0;
D = b^2 - 4ac;
D = -6^2 - 4 * 9 * 1;
D = 36 - 36 = 0;
D = 0, один корень!
x = -b/2a;
x = 6/(2*9);
x = 6/18; |:6
x = 1/3;
Ответ: 1/3.
Ответ 15
-2.1+(-7х)=0.9-7.2х
-7х+7.2х=0.9+2.1
0.2х=3|:0.2
х=15
<span>a^4+4a^3*b+6a^2*b^2+4a*b^3+b^4</span>