( 1/4 )^x - ( 1/2 )^( x - 1 ) = 8
( 1/2 )^2x - ( 1/2 )^x * 2 = 8
( 1/2 ) ^x = a
a^2 - 2a - 8 = 0
D = 4 + 32 = 36 = 6^2
a1 = ( 2 + 6 ) : 2 = 4
a2 = ( 2 - 6 ) : 2 = - 2 ( < 0 )
( 1/2 ) ^ x = 4
2 ^ ( - x ) = 2 ^ 2
- x = 2
x = - 2
A)cos^2a+sin^2a=1
1+tg^2a=1+tg^2a
b)-cos^2a+1=sin^2a
2sin^2a=2sin^2a
c)sin^2a-1=-cos^2a
-cos^2a= -cos^2a
А) 3а+7б-6а-4б
-3а+3б
б)8с+(5-с)-(7+11с)
8с+5-с-7-11с
-4с-2
<span>в)4-5(3у+8)
</span>4-15у-40
-15у-36
F(-2,1) = 2,1^2-4/-2,1-2 = 4,41-4/-4,1 = 0,41/-4,1 = -0,1