2*1/2-1+√3=1-1+√3=√3
√3+2*√2/2-√3*1=√3+√2-√3=√2
6*√3/2-3*√3+2*√2/2=3√3-3√3+√2=√2
A) an=a1+d(n-1)
50=10+4(n-1)=10+4n-4
50=6+4n
4n=50-6=44
n=44/4
n=11
Sn=((a1+an)/2)*n
S(11)=((10+50)/2)*11=(60/2)*11=30*11
S(11)=330
b) 10+4(n-1)=14
10+4n-4=14
4n=14-6=8
n=8/4
n=2
S(2)=((10+14)/2)*2=(24*2)/2=24
Решение
x² - y = - 2
2x + y = 2
y = x² + 2
2x + x² + 2 = 2
x² + 2x = 0
x(x + 2) = 0
x₁ = 0
x + 2 = 0
x₂ = - 2
x₁ = 0
y₂ = 2
(0; 2)
x₂ = - 2
y₂ = (-2)² + 2 = 6
(-2; 6)
Ответ: (0; 2) ; <span>(-2; 6)</span>