D=b²-4ac
<span>------------------
5х²-4х-1=0
D</span>=(-4)²-4*5*(-1)=16+20=36=6²
<span>----------------------
3х-х²+10=0
D=</span>(3)²-4*(-1)*10= 49 = 7²
---------------------------------
<span>х²-6х+9=0
D</span>=(-6)²-4*1*9=36-36=0
----------------
2х+3+2х²=0<span>
D=</span>2²-4*2*3=4-24=-20
36-4х=7+2х
36-7=4х+2х
29=6х
Х=4 5/6
Ответ: 4 5/6
<span>1. y'=(x^5-2,5x</span>²<span>+3)'=5x^4-5x;
5x^4-5x=0;
5x(x</span>³-1)=0;
<span>x=0, x=1.
f(0)=0^5-2,5*0</span>²+3=3;
<span>f(1)=1^5-2,5*1</span>²+3=1-2,5+3=1,5.<span>
2. y'=(0,2x^5-4x^2-3)'=x^4-8x;
x^4-8x=0;
x(x</span>³-8)=0;
x-0, x=2.
f(0)=0,2*0^5-4*0²-3=-3;
f(2)=0,2*2^5-4*2²-3=-12,6.
4A+3a=130
A+a=36
A=36-a
4(36-a)+3a=130
144-4a+3a=130
-a=-14
a=<em><u>14</u></em>
A=36-14=<u><em>22</em></u>
<u><em>Ответ: 22 в тяжелом и 16 в легком</em></u>