-2х^2-3x-1=0
D=9-4*(-2)*(-1)=9-8=1
x1=(3+1)/-4=4/-4=-1
x2=(3-1)/-4=2/-4=-0.5
2x - 4(3x + 9) ≥ - 3
2x - 12x - 36 ≥ - 3
- 10x ≥ - 3 + 36
- 10x ≥ 33
x ≤ - 3,3
x ∈ (- ∞ ; - 3,3]
<span><span>(у+10)(у-2)-4у(2-3у)</span>=у²-2у+10у-20-8у+12у²=</span>(у²+12у²)+(-2у+10у-8у)-20=<span>13у²-20</span>
F(2+√7)=7-(2+√7)²=7-(4+4√7+7)=-4-4√7
f(2-√7)=7-(2-√7)²=7-(4-4√7+7)=-4+4√7
[ f(2+√7)-f(2-√7) ]/ [ f(2-√7)+f(2+√7) ]=[ (-4-4√7)-(-4+4√7) ] / [ (-4+4√7)+(-4-4√7) ]=-8√7/(-8)=√7
(a² -25) /(2a² +10a) =(a -5)(a +5) /2a(a +5) =(a -5) /2a,
при а =0