1.Rezolvati in N ecuatiile: a) 16-2x=0 ,b) 3x-7=0 , c) 3x+9=5-x
2.Rezolvati in Z ecuatiile: a) 3x -123=0 b) 2x+9=0 c) -7x+91=0
3.Rezolvati in Q ecuatiile: a) 3(2x-5)+7=4x-13 c) 3(2-x)+8=2x-1
4.Rezolvati in R ecuatiile: 2radical din 3x + radical din 48 =0 !

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Va rog frumos ajutatima rapid(spunetimi cum se rezolva, nu doar raspunsu,ca am uitat :( )

Răspunsuri

2014-09-05T09:49:11+03:00
1. a) 16-2x =0                        
-2x = - 16 / x (-1)
2x= 16/:2
x=8

b) 3x-7=0
3x = 7 / :3
x = 7/3

c) 3x+9 = 5-x
3x+x = 5-9
4x = -4 / :4
x= -1

2. a) 3x-123 = 0
3x = 123 / :3
x =41

b) 2x+9 = 0
2x = -9 / :2
x = - 9/2

c) -7x + 91 = 0
-7x = -91 / x (-1)
7x = 91 / : 7
x = 13

3. a) 3(2x-5)+7 = 4x-13
6x-15 + 7 = 4x-13
6x - 4x = -13 -7 +15
2x = -5 / :2
x = - 5/2  

c) 3(2-x) + 8 = 2x-1
6-3x + 8 = 2x-1
-3x - 2x = -1 -8 -6
-5x = -15 / x (-1)
5x = 15 / :5
x = 3

4) 2√3x + √48 = 0
2√3x = - 4√3 ( aici am scos factorii de sub radical ) / : 2√3
x = - 2.


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