Question

8). Rezolvati exuatiile:
b). -9+7=5x+11
c). 6x-13=2x-1
d). 2,5x-3(1,5x+2)=4,7
e). 5x-9-2x=19
f). 2x+1/2=0,75+1/3x
g). 2x+1/3=-0,(6)
h). 6+5(3x-3)/2=13-2(2x-4)
i). 3(x-5)/2=5x-18

Answer 1

-9+7=5X+11
-5x=11+2
x=-13/5

6x-13=2x-1
6x-2x=-1+13
4x=12
x=12:4
x=3

2,5x-3(1,5x+2)=4,7
2,5x-4,5x-6=4,7
-2x=4,7+6
-x=10,7:2
x=-5,35

5x-9-2x=19
3x=19+9
x=28/3
x=9,33

2x-1/2=0,75+1/3*x
2x-x/3=1,75+0,5
6x/3-x/3=2,25
5x/3=2,25
x=2,25*3/5
x=1,35

2x+1/3=-0,(6)
2x=-0,6-0,3
x=-0,9:2
x=-0,45

6+5(3x-3)/2=13-2(2x-4)
6+(15x-15)/2=13-4x+8
15x/2-15/2+4x=21-6
15x/2+28x/2=15+7,5
43x/2=22,5
x=22,5*2/43
x=1,046

3(x-5)/2=5x-18
(3x-15)/2=5x-18
3x/2-15/2-5x=-18
3x/2-10x/2=15/2-18
-7x/2=7,5-18
-x=-10,5*2/7
x=3

Answer 2

b)-13=5x, x=-13/5
c)4x=12, x=3
d)2,5x-4,5x-6=4,7,    -2x=10,7, x=-10,7/2
e)3x=28, x=28/3
f)(4x+1)/2=(0,75.3x+1)/3x  sau (4x+1)3x=2(0,75.3x+1), sau 
12xpatrat+3x=4,5x+2, sau 12xpatrat-1,5x-2=0....se pare ca e gresit!!, 3x nu era la numitor cum ai scris, trebuia x/3!
Asa ca trebuia (4x+1)/2=(3.0,75+x)/3, sau 3(4x+1)=2(2,25+x), sau
12x+3=4,5+2x, sau 10x=1,5, x=1,5/10=0,15
g)(6x+1)/3=-6/9, sau 6x+1=-2, x=-3/6=-1/2
h)6+(15x-15)/2=13-4x+8, sau aduci la numitor comun si obtii:
12+15x-15=26-8x+16, sau 23x=45, x=45/23
i)3x-15=10x-36, sau -7x=21, x=-3