A1+2d+a1+3d=2a1+5d=5/12
S6=(2a1+5d)*6/2=5/12*3=5/4
1) log(√7)(1/7)+3^log₃7=log(7^(1/2)7⁻¹+7=-2log₇7+7=-2+7=5.
2) √(25^(1/log⁶5)+49^(1/log₈7))=√(5^2log₅6+7^2log₇8)=
=√(5^log₅6²+7^log₇8²)=√(6²+8²)=√100=10.
3) 10^(1-lg5)=10*10^(-lg5)=10/10^lg5=10/5=2.
4) log(c)(16c²)=log(c)4⁴+log(c)c²=4log(c)2+2=4*(-3)+2=-10.
11+4х > 2х -7
2х > -18
х > -9
5 - 4х =< 7х - 5
0 =< 11х
х >= 0
14 +2(-х+7) =< 24 - 3(х-1)
14 + 14 - 2х =< 24+3 - 3х
28 - 2х =< 27 - 3х
1 <= -х
х >= 1
|х| + 7 <= 10
|х| <= 3
-3 < х < 3
А)8х-5=х-40
8х-х=-40+5
7х=-35
Х=-35:7
Х=-5
Б)7х+22=х-14
7х-х=-14-22
6х=-36
Х=-36:6
Х=-6
В)19-6х=0
-6х=-19
Х=-19:(-6)
Х= 19
—
6