1) a, a≥0
IaI=
2) -a, a строго меньше 0
x- 3 может быть,как меньше 0 ,так и больше,значит у тебя два варианта будет x-3 и -(x-3)
Log(a)b=log(c)b/log(c)a
log(a^n)(b^n)=log(a)b
nlog(a)b=log(a)b^n
-------------------------------------------------
a)
log(6)4+log(6)9+1/log(6)4 *2log(6)2 +2=log(6)(4*9)+log(6)4/log(6)4+2=
=log(6)36+1+2=2+3=5
б)
log(2)10+log(2)12-log(2)30 +4=log(2)(10*12/30)+4=log(2)4+4=2+4=6
в)
log(2)6+log(2)10-log(2)15+2^log(2)5=log(2)(6*10/15)+5=log(2)4+5=2+5=7
Используешь обычные методы решения с квадратами
3,8*8*10⁻³*10⁻³=30.4*10⁻⁶=3.04*10⁻⁷
<span>(2x-5)(x+7)(x+1) ≥ 0
2x-5≥0
x-7≥0
x+1≥0
</span>
<span><span>2x≥5
x≥7
x≥-1</span>
</span>
<span>x≥2.5
x≥7
x≥-1</span>
x(7;+∞)
![\frac{5 ^{-9} *5 ^{-2} }{5 ^{-8} } =5^{-9+(-2)-(-8)}=5^{-9-2+8}=5^{-3}](https://tex.z-dn.net/?f=+%5Cfrac%7B5+%5E%7B-9%7D+%2A5+%5E%7B-2%7D+%7D%7B5+%5E%7B-8%7D+%7D+%3D5%5E%7B-9%2B%28-2%29-%28-8%29%7D%3D5%5E%7B-9-2%2B8%7D%3D5%5E%7B-3%7D)
![( \frac{1}{7a} + \frac{1}{2a} ) * \frac{a^{2} }{4} = \frac{2+7}{14a} * \frac{a^{2} }{4}=\frac{9}{14} * \frac{a }{4}= \frac{9a}{56} \\ a=-2.8 \\ \frac{9*(-2.8)}{56} =\frac{-25.2}{56} =-0.45](https://tex.z-dn.net/?f=%28+%5Cfrac%7B1%7D%7B7a%7D+%2B+%5Cfrac%7B1%7D%7B2a%7D+%29+%2A+%5Cfrac%7Ba%5E%7B2%7D+%7D%7B4%7D+%3D+%5Cfrac%7B2%2B7%7D%7B14a%7D++%2A+%5Cfrac%7Ba%5E%7B2%7D+%7D%7B4%7D%3D%5Cfrac%7B9%7D%7B14%7D++%2A+%5Cfrac%7Ba+%7D%7B4%7D%3D+%5Cfrac%7B9a%7D%7B56%7D++%5C%5C+a%3D-2.8+%5C%5C+%5Cfrac%7B9%2A%28-2.8%29%7D%7B56%7D++%3D%5Cfrac%7B-25.2%7D%7B56%7D++%3D-0.45)