8.
3(-3-1)-a=2*(-3)-4
3*(-4)-a=-6-4
-12-a=-10
a=-12+10
a=-2
9.
1b
2d
3a
4c
10.
(x+1)^2-7^2=0
(x+1+7)(x+1-7)=0
(x+8)(x-6)=0
x=-8
x=6
11.
a)
x=5,-5
b)
Absurd - nu are soluții
Modulul este mereu pozitiv
c)
2x-1=7, 2x=8, x=4
2x-1=-7, 2x=-6, x=-3
d)
-x+2=5, x=-3
-x+2=-5, x=-7
12.
a) 3x=9, x=3
b) 4x=16, x=4
c) 3x-3=6, 3x=9, c=3
d) 3x+6=2x-2
x=-8
e) 4x=8, x=2
f) x+3=0, x=-3
x-2=0, x= 2
d)
