Odpowiedzi

2010-03-07T17:08:46+01:00
1.
½ x + 5 = x + 8
½x-x=8-5
-½x=3
x=-6


2.
a.
97 = 2x - 5
-2x=-5-97
-2x=-102
x=51

b.
43=7+9x
-9x=7-43
-9x=-36
x=4

c.
17=11-12x
12x=11-17
12x=-6
x=-0,5

d.
3 ⅔ = ½x - ⅓
-½x=-⅓-3⅔
-½x=-4
x=8

2010-03-07T17:12:26+01:00
½ x + 5 = x + 8
1/2 x - x= 8 -5
-1/2x= 3 /*2
-x= 6 /*-1
x= -6




2. a. 97 = 2x - 5
2x-5=97
2x= 97+5
2x= 102
x= 51


b. 43=7+9x
7+9x=43
9x=43-7
9x=36
x=4



c. 17=11-12x
11-12x=17
-12x=17-11
-12x=6 /12
-x= 1/2 /-1
x= -1/2



d. 3 ⅔ = ½x - ⅓
½x - ⅓ =3 ⅔
½x=3 ⅔ + ⅓
½x= 4 /½
x= 8

2010-03-07T17:17:52+01:00
1. ½x+5=x+8 |*2
x+10 = 2x+16
-6=x
x= -6

2.
a) 97-2x-5
102=2x |:2
51=x
x=51

b) 43=7+9x
36=9x |:9
4=x
x=4

c) 17=11-12x
6=-12x |:(-12)
-0,5=x
x=-0,5

d) 3 ⅔ = ½x - ⅓ |*6
6(3 ⅔)= 3x -2
⁶⁶/₁₁ = 3x -2
22=3x-2
24=3x |:3
8=x
x=8