Question

Determinati solutiile ecuatiilor:
a.4(x+5)-5(x+3)=x-5
b.4x+1+2(x-5)=5(x+1)
c.2(x+3)-3(2x+1)=8(2x-9)-9
d.3(2x+3)-2(3x+2)= -3(x+2)+2
e.-3x+5-4(x-1)=-2(x+1)-24
f.x-15+3(x+1)=5(x-2)+11
g.5(x+2)-2(2x+3)=34-5x

Answer 1

a) 4(x + 5) - 5(x + 3) = x - 5
    4x + 20 - 5x - 15 = x - 5
    - 2x = - 10       x = 5
b) 4x + 1 + 2(x - 5) = 5(x + 1)
    4x + 1 + 2x - 10 = 5x + 5
    6x - 5x = 5 - 1 + 10
    x = 14
c) 2(x + 3) - 3(2x + 1) = 8(2x - 9) - 9
    2x + 6 - 6x - 3 = 16x - 72 - 9
    - 4x - 16x = - 81 - 3
     20x = 84      x = 84/20⁽⁴ = 21/5
d) 3(2x + 3) - 2(3x + 2) = - 3(x + 2) + 2
     6x + 9 - 6x - 4 = - 3x - 6 + 2
     3x = - 5 - 4
     x = - 9/3 = - 3    
e) - 3x + 5 - 4(x - 1) = - 2(x + 1) - 24
    - 3x + 5 - 4x + 4 = - 2x - 2 - 24
     - 7x + 2x = - 9 - 26
     - 5x = - 35         x = 35/5 = 7
 f) x - 15 + 3(x + 1) = 5(x - 2) + 11
    x - 15 + 3x + 3 = 5x - 10 + 11
    4x - 5x = 12 + 1
    x = - 13
g) 5(x + 2) - 2(2x + 3) = 34 - 5x
    5x + 10 - 4x - 6 = 34 - 5x
    x + 5x = - 4 + 34
    6x = 30
    x = 30/6 = 5