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Rezolvati in R :

a. 2x+8 -1,5(x+5) = x+10

b. [tex] \frac{x+4}{7} - \frac{5}{2} = \frac{x-9}{2} [/tex]

c. [tex] \frac{5x-7}{2} - \frac{2x+7}{3} = 3x - 14[/tex]

d. [tex] \frac{3x+1}{5} - \frac{x-6}{2} = \frac{2x+5}{5} + \frac{16}{5} [/tex]



Răspuns :


a)2x+8-1,5(x+5)=x+10b

2x+8-1,5x-1,5*5=x+10b

2x-1,5x-x=10b+1,5*5

-0,5x=10b+7,5    

x=-20b-15

b)(x+4)/7-5/2=(x-9)/2      numitor comun 14 (eliminam numitorul)

  2x+8-35=7x+63          ⇒5x==-90 ⇒x=-18

c)(5x-7)/2-(2x+7)/3=3x-14

15x-21-4x-14=18x-14.6

11x-18x=84+21

-7x=105

x=-15

d)(x+1)/5-(x-6)/2=(2x+5)/5+16/5

6x+2-5x+30=4x+10+32

-5x=10        ⇒x=-2