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29 Rezolvați ecuațiile: c |-x+2|=1; d |2x+4=8; e |3x-7=5; |x-2=5; bx+3=3; f-x+4=11; g|-2x-6=12; h |12-x=-24; 1-15x+10=-20.
dau coroana repede​


Răspuns :

Răspuns:

c. x+2=1

x=2-1=1

d. 2x-4=8

2x=8+4

2x=12

x=12:3

x=6

e. 3x+7=5

3x=5-7

3x=-2

x= -2:3

x+2=5

x-2=5

x=5+3

x=8

-2x-6=12

-2x=12+6

-2x=18/×(-1)

2x=-18

x= -18 : 2

x= -9

h. 12-x=24

x=24-12

x= 12

1-15x+10=20

1-15x=20-10

1-15x=10

-15x=10-1

-15x=9/×(-1)

15x=-9

x = -9 : 15

[tex]\it c)\ \ |-x+2|=1 \Rightarrow |x-2|=1 \Rightarrow x-2\in\{-1,\ 1\}\bigg|_{+2} \Rightarrow x\in\{1,\ \ 3\}\\ \\ \\ d)\ \ |2x+4|=8 \Rightarrow 2x+4=\pm8\bigg|_{:2} \Rightarrow x+2=\pm4 \Rightarrow \\ \\ \Rightarrow x+2\in\{-4,\ 4\}\bigg|_{-2} \Rightarrow x\in\{-6,\ 2\}[/tex]

[tex]\it e)\ \ |3x-7|=5 \Rightarrow 3x-7=\pm5 \Rightarrow 3x-7\in\{-5,\ 5\} \bigg|_{+7}\Rightarrow \\ \\ \Rightarrow 3x\in\{2,\ 12\}\bigg|_{:3} \Rightarrow x\in\bigg\{\dfrac{2}{3},\ 4\bigg\}[/tex]

[tex]\it h)\ \ |12-x|=-24 \Rightarrow ecua\c{\it t}ie\ imposibil\breve a, \ deoarece\ modulul \ nu \ poate\ fi\ negativ\\ \\ Mul\c{\it t}imea\ solu\c{\it t}iilor\ este\ mul\c{\it t}imea \ vid\breve a\ .\ \ \ S=\O[/tex]