40+20=60*2=120-70=50:5=10
100*8=800-300=500+320=820:2=410
80:4=40*6=240+80=320+800=1120
A) P(m=2)= 30/40·10/39=5/26≈0.19
б) P(m>2)=1-P(m≤2)=1-P(m=1)=P(m=2)=1-10/40-0.19=1-0.25-0.19=0.56
в) P(m<5) =P(m=1)+P(m=2)+P(m=3)+P(m=4)=0.25+0.19+30/40·29/39·10/38+
+<span>30/40·29/39·28/38</span>·10/37≈0.25+0.19+0.15+0.11=0.7
<span>x^2+2x=3
x</span>² + 2x - 3 = 0
D = b² - 4ac
D = 2² - 4 * 1 * (-3) = 4 + 12 = 16 > 0 ⇒ уравнение имеет 2 корня
√D = 4
x₁ = (-2 + 4) / 2 = 2 / 2 = 1
x₂ = (-2 - 4) / 2 = -6 / 2 = -3