1/( x - 1 )^2 + 2/( x - 1 ) - 3 = 0
( 1 + 2( x - 1 ) - 3( x - 1 )^2 ) / ( x - 1 )^2 = 0
X не равен 1
1 + 2х - 2 - 3х^2 + 6х - 3 = 0
- 3х^2 + 8х - 4 = 0
3х^2 - 8х + 4 = 0
D = 64 - 48 = 16 = 4^2
X1 = ( 8 + 4 ) : 6 = 2
X2 = ( 8 - 4 ) : 6 = 2/3
Ответ 2 ; 2/3
А) 4m*(3+5m)-10m*(6+2m)= m2 и а2 это в квадрате
12m+20m2-60m-20m2=
= - 48m
б)2а*(3а-5)-(а-3)*(а-7)=
6а2-10а-(а2-7а-3а+21)=
6а2-10а-а2+7а+3а-21= 5а2-21
5)
0.4х=-0.44
х=-0.44÷0.4
х=-1.1
6)
1/3х+1/9х=2/7-5/7
3/9х+1/9х=-3/7
4/9х=-3/7
х=-3/7÷4/9
х=-3/7×9/4=-27/28
7)
12а+15=17а-5
17а-12а=15+5
5а=20
а=4
4)
номер 4
1)5х-20=х+8
5х-х=8+28
4х=28
х=7.
2)9-7х-21=5-6х
-7х+(-6х)=5+21-9
-х=17 |:(-1)
х=-17.
3)7х+9-11х+7=8
-4х=8-7-9
-4х=-8 |:(-4)
х=2.