Question

Rezolvați in multimea numerelor reale următoarele ecuații:
a) 1,25x=0,2(7)
b) 0,6(1)x=2,75
c) -2,5x=1,3(8)
d) 1+1,(3)x=2,5

Answer 1

Răspuns:

Explicație pas cu pas:

a) 1,25x=0,2(7) <=>

125x/100 = (27-2)/90 <=>

5x/4 = 25/90 <=>

5x/4 = 5/18 =>

18·5x = 5·4 =>

x = 4/18 =>

x = 2/9 = 0,(2)

b) 0,6(1)x=2,75 <=>

(61-6)x/90 = 275/100 <=>

55x/90 = 11/4 <=>

11x/18 = 11/4  => x = 198/44 = 99/22 = >

x = 9/2 = 4,5

c) -2,5x=1,3(8) <=>

-25x/10 = (138-13)/90 <=>

-5x/2 = 125/90 =>

-5x/2 = 25/18 =>

x = -50/90 = >

x = -5/9 = - 0,(5)

d) 1+1,(3)x=2,5 <=>

(13-1)x/9 = 1,5 <=>

12x/9 = 15/10 <=>

4x/3 = 3/2 =>

x = 9/8 = 1,125