X=11-12y
5(11-12y)-3y+8=0
55-60y-3y+8=0
-63y+63=0
-63y=-63
y=1
x=11-12*1=11-12= -1
Ответ: (-1; 1)
an=-4.1+8.9n n=15 a15=-4.1+8.9*15=129.4
Ответ:
Объяснение:
2⁻²+3⁻¹x=0,25
2⁻²+3⁻¹x=1/4
3⁻¹x=2⁻²-2⁻²
x/3=0
x=0
2,25x=5,125-4⁻¹x
9/4 ·x=41/8 -1/4 ·x
9/4 ·x+ 1/4 ·x=41/8
10/4 ·x=41/8
x=41/8 ·4/10=41/20=2 1/20=2,05
4⁻¹x-2⁻²x=8²+x
(2²)⁻¹x-2⁻²x-x=64
2⁻²x-2⁻²x-x=64
0-x=64
x=-64
X+5 >или равно 3
<span>X > или равно -2</span>
A3 - a1 = 6
a3 = a1 + d(3-1) = a1 + 2d
a1 + 2d - a1 = 6
2d = 6
d = 3
a3 * a1 = 27
(a1 + 2d) * a1 = 27
a1^2 + 2d*a1 - 27 = 0
a1^2 + 6*a1 - 27 = 0
D = 36 + 108 = 144
a1 = (-6 - 12)/2 = -9 и a1=(-6+12)/2 = 3
Ответ: a1 = 3 и -9