Question

Rezolvatu in R ecuatiile :
a. 3|2x+1|=6
b. ||-x+1|+7|=12
( | = modul)​

Answer 1

Răspuns:

a) 3|2x+1|=6 /:3

|2x+1 |= 2

2x+1=2

2x=2-1

2x=1 /:2

x= 1/2, x € R

-(2x+1)=2

-2x-1=2

-2x=2+1

-2x=3 /:(-2)

x= - 3/2 , x € R

x 1 =1/2

x 2 = - 3/2

x € R

b) ||-x+1|+7|=12

7 este pozitiv deci dispare al doilea modul

|-x+1|+7=12

|-x+1|=12-7

|-x+1|=5

-x+1=5

-x=5-1

-x=4 /×(-1)

x= -4 , x € R

-(-x+1)=5

x-1 = 5

x=5+1

x= 6 , x € R

x 1 = -4

x 2 = 6

x € R

Explicație pas cu pas: