Question

Exercițiul 7 cel însemnat.
Vă rog!

Answer 1

a) 12 x- 3= 21
12 x= 24
x=2
b) 15 x+ 6= 36
15x=30
x=2
c) 12x- 6= -18
12x= -12
x= -1
d) -12x+18=30
-12x= 12
x= -1
e) -10x+15=8x-3
-18x= -18
x=1
f) 6x- 15= 21
6x= 36
x=6
g) 15x-20=6x+7 
9x=27
x=3
h) -4x+12=16
-4x=4
x=-1
i) 14x+4=18
14x=14
x=1
j) 12x-12=48
12x=36
x=3
k) 24x-4=20x
4x=4
x=1
l) 14x+14= 13x
x=-14

Answer 2

a)3×(4x-1)=21
4x-1=21:3
4x-1=7
4x=8
x=8:4
x=2
b)3×(5x+2)=36
5x+2=36:3
5x+2=12
5x=12-2
5x=10
x=2
c)6×(2x-1)=-18
2x-1=-18:6
2x-1=-3
2x=-3+1
2x=-2
x=-1
d)-3 (4x+6)=30
4x+6=-10
4x=-16
x=-4
e)-5×(2x-3)=8x-3
-10x+15=8x-3
-18x=-18
x=1
f)3 (2x-5)=21
2x-5=7
2x=12
x=6
g)5×(3x-4)=6x+7
15x-20=6x+7
9x=27
x=3
h)-4×(x-3)=16
x-3=-4
x=-1
i)2×(7x+2)=18
7x+2=9
7x=7
x=1
j)12 (x-1)=48
x-1=48:12
x-1=4
x=4+1
x=5
k)4 (6x-1)=20x
24x-4=20x
4x=4
x=1
l)14 (x+1)=13x
14x+14=13x
14x-13x=-14
x=-14