An = a1*q^(n-1) = 567
a1 + a2 + ... + an = a1 + a1*q + ... + a1*q^(n-1) = a1 * (q^n - 1)/(q - 1) = 847
q = 3
a1 * 3^n / 3 = 567
a1 * (3^n - 1)/2 = 847
a1 * 3^n = 1701
a1 * 3^n - a1 = 1649
{вычитаем из первого равенства второе}
a1 = 7
А)-7 12/23-5,93-71 13/27-(-7 12/23)-6,07=-7 12/23-5,93-71 13/27+7 12/23)-6,07=(-7 12/23+7 12/23)+(-5,93-6,07)-71 13/27=0-12-71 13/27=-83 13/27
б)-25-24-23-...-1+0+1+...+32+33=(-25+25)+(-24+24)+...+(-1+1)+0+
+26+27+28+29+30+31+32=236
4y = 4y
( 3x + 1 )*2 = ( x + 3 )*2
6x + 2 = 2x + 6
4x = 4
x = 1
4y = 2x + 6
4y = 2 + 6
4y = 8
y = 2
ОТВЕТ ( 1 ; 2 )
1a) 5x + (3x - 7) = 9 б) 3y - (5 - y) = 11 в) 48 = 11 - (9a + 2)
5x + 3x - 7 = 9 3y - 5 + y = 11 48 = 11 - 9a - 2
8x = 9 + 7 4y = 11 + 5 9a = 9 - 48
8x = 16 4y = 16 9a = - 39
x = 2 y = 4 a = - (4)1/3
г)13 - (5x + 11)= 6x
13 - 5x - 11 = 6x
- 5x - 6x = 11 - 13
- 11x = - 2
x = 2/11
2a) (7x + 1) - (6x + 3) = 5
7x + 1 - 6x - 3 = 5
x = 5 - 1 + 3
x = 7
б)(8x + 11) - 13 = 9x - 5
8x + 11 - 13 = 9x - 5
8x - 9x = - 5 - 11 + 13
- x = - 3
x = 3
в) 2 = (3x - 5) - (7 - 4x)
2 = 3x - 5 - 7 + 4x
- 3x - 4x = - 5 - 7 - 2
- 7x = - 14
x = 2
г) 8x + 5 = 119 + (7 - 3x)
8x + 5 = 119 + 7 - 3x
8x + 3x = 119 + 7 - 5
11x = 121
x = 11
(9/22+1 12/33)*1,32-8/13*0,163=117/66*132/100-1304/13000=15444/6600-1304/13000=7279/3250=2 779/3250