фоточка тебе в
1. xn=2n-1;
n=1; x1=2*1-1=2-1=1;
n=2; x2=2*2-1=4-1=3;
n=3; x3=2*3-1=6-1=5;
n=4; x4=2*4-1=8-1=7;
n=5; x5=2*5-1=10-1=9.
***
2. xn=n²+1;
n=1; x1=1²+1=2;
n=2; x2=2²+1=5;
n=3; x3=3²+1=10;
n=4; x4=4²+1=17;
n=5; x5=5²+1=26.
***
3. xn=1/(n+1);
n=1; x1=1/(1+1)=1/2;
n=2; x2=1/(2+1)=1/3;
n=3; x3=1/(3+1)=1/4;
n=4; x4=1/(4+1)=1/5;
n=5; x5=1/(5+1)=1/6.
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4. xn=(-1)^n;
n=1; x1=(-1)^1=-1;
n=2; x2=(-1)^2=1;
n=3; x3=(-1)^3=-1;
n=4; x4=(-1)^4=1;
n=5; x5=(-1)^5=-1.
Объяснение:
1. xn=2n-1;
n=1; x1=2*1-1=2-1=1;
n=2; x2=2*2-1=4-1=3;
n=3; x3=2*3-1=6-1=5;
n=4; x4=2*4-1=8-1=7;
n=5; x5=2*5-1=10-1=9.
***
2. xn=n²+1;
n=1; x1=1²+1=2;
n=2; x2=2²+1=5;
n=3; x3=3²+1=10;
n=4; x4=4²+1=17;
n=5; x5=5²+1=26.
***
3. xn=1/(n+1);
n=1; x1=1/(1+1)=1/2;
n=2; x2=1/(2+1)=1/3;
n=3; x3=1/(3+1)=1/4;
n=4; x4=1/(4+1)=1/5;
n=5; x5=1/(5+1)=1/6.
***
4. xn=(-1)^n;
n=1; x1=(-1)^1=-1;
n=2; x2=(-1)^2=1;
n=3; x3=(-1)^3=-1;
n=4; x4=(-1)^4=1;
n=5; x5=(-1)^5=-1.
2.
(х-5)/(х+3) + 5/(х-3) = 48/(х²-9),
(х-5)(х-3)/(х²-9) + 5(х+3)/(х²-9) = 48/(х²-9),
(х²-3х-5х+15+5х+15)/(х²-9) = 48/(х²-9),
(х²-3х+30)/(х²-9) = 48/(х²-9),
(х²-3х+30-48)/(х²-9) = 0,
(х²-3х-18)/(х²-9) = 0,
ОДЗ:
х² - 9 ≠ 0,
(х - 3)(х + 3) ≠ 0,
х - 3 ≠ 0, х + 3 ≠ 0,
х ≠ 3, х ≠ -3,
х² - 3х - 18 = 0,
Д = (-3)² - 4*1*(-18) = 9 + 72 = 81,
х1 = (3 + 9) / 2*1 = 12/2 = 6,
х2 = (3 - 9) / 2*1 = -6/2 = -3,
ответ: х = 6,
3.
(х-6)/(х+1) - (2+х)/(1-х) = 6/(х²-1),
(х-6)/(х+1) + (2+х)/(х-1) = 6/(х²-1),
(х-6)(х-1)/(х²-1) + (2+х)(х+1)/(х²-1) = 6/(х²-1),
(х²-х-6х+6+2х+2+х²+х)/(х²-1) = 6/(х²-1),
(2х²-4х+8)/(х²-1) = 6/(х²-1),
(2х²-4х+8-6)/(х²-1) = 0,
(2х²-4х+2)/(х²-1) = 0,
ОДЗ:
х² - 1 ≠ 0,
(х - 1)(х + 1) ≠ 0,
х - 1 ≠ 0, х + 1 ≠ 0,
х ≠ 1, х ≠ -1,
2х² - 4х + 2 = 0,
х² - 2х + 1 = 0,
Д = (-2)² - 4*1*1 = 4 - 4 = 0,
х = 2 / 2*1 = 2/2 = 1,
ответ: корней нет
Объяснение:
0,4t(t^3+g)−0,8g(t^3+g) = (t^3+g) (0,4t-0,8g)= 0,4(t³+g)(t-2)