2^( - x + 1) = (1/2)^( - x + 3)
2^( - x + 1) = 2^( x - 3)
- x + 1 = x - 3
- x - x = - 3 - 1
- 2x = - 4
2x = 4
x = 2
129.
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1) ( 0,1) ^ (- Lg 0,3 ) =(10⁻¹ )* ^ (- Lg 0,3 ) =(10)* ^ (Lg 0,3 <span>) = 0,3 .
2) 10 ^(-Lg4) = </span>10 ^(Lg4 ⁻¹ ) = 4 ⁻<span>¹ = 1/4. || 0,25 ||
3) 5 ^( -Log 5 3) = </span> 5 ^( Log 5 3 ⁻¹ ) = 3 ⁻<span>¹ =1/3.
4) 1/ 6 ^(-Log 6 4) =( 6</span>⁻¹)^ (-Log 6 4) =6^ (Log 6 4) ) <span> =4.
130.
</span>------<span>
1) 4Log(1/2) 3 -(2/3) Log (</span>1/2) 27 -2 Log (<span>1/2) 6 =
</span>Log(1/2) 3⁴ - Log (1/2) (3³)^(2/3) - Log (1/2) 6² =
Log(1/2) 3⁴ - Log (1/2) 3² - Log (1/2) 6² = Log(1/2) 3⁴/(3²* 6<span>²) =
</span>Log(1/2) 3²/ 6² = Log(1/2) (3/ 6)² = Log(1/2) (1/ 2)<span>² <span>=2.
</span>или по другому:
</span>4Log(1/2) 3 -(2/3) Log (1/2) 27 -2 Log (<span>1/2) 6 =
</span>4Log(1/2) 3 - (2/3)Log( 1/2) 3³ -2 Log (1/2) 6 =
4Log(1/2) 3 - 2 Log (1/2) 3 - 2Log (1/2) 6 =2Log(1/2) 3 - 2 Log (1/2) 6=
2*(Log(1/2) 3 - Log (1/2) 6 ) =2 Log (1/2) (3/6 )=2 <span>Log (1/2) (1/2 ) =2</span>
Log(1/2) 3²/ 6² = Log(1/2) (3/ 6)² = Log(1/2) (1/ 2)<span>² <span> =2.</span></span>
2) ( 2/3)*Lg0,001 +Lg ∛1000 -(3/5)*Lg √10000 =
( 2/3)*Lg10⁻³ +Lg ∛10³ -(3/5)*Lg √10⁴ = ( 2/3)*(-3) +Lg10 -(3/5)*Lg 10² = <span>
(2/3)*(-3) +1 -(3/5)*2 = -2 +1 - 1,2 = - 2,2 .</span>
А 25,б 25,в 19, г 25,д -25, е -25, ж 13,з 1, ц вроде 0
A1+a1+d+a1+2d=21⇒3a1+3d=21⇒a1+d=7⇒d=7-a1
{a1+d-1=a1q⇒a1+7-a1-1=a1q⇒a1q=6
a1+2d+1=a1q²⇒a1+14-2a1+1=a1q²⇒a1q²=15-a1
15-a1=6q
q=(15-a1)/6
a1(15-a1)/6=6
15a1-a1²=36
a1²-15a1+36=0
(a1)1+(a1)2=15 U (a1)1*(a1)2=36
(a1)1=3⇒d1=7-3=4
(a1)2=12⇒d2=7-12=-5
Ответ 3;7;11 или 12;7;2
1х-2х+4х-8х=1
-5х=1
х= - 0,2