Răspuns:
c) x = -3
d) c = -14/23
Explicație pas cu pas:
c)
[tex]\frac{x}{3} - \frac{1}{5} = \frac{4x}{15} - \frac{2}{5}[/tex]
[tex]\frac{x}{3} - \frac{4x}{15} = -\frac{2}{5} +\frac{1}{5}[/tex] (am separat termenii)
[tex]\frac{5x}{15} - \frac{4x}{15} = -\frac{1}{5}[/tex]
[tex]\frac{x}{15} = -\frac{1}{5}[/tex]
[tex]x = -\frac{15}{5}[/tex]
x = -3
d)
[tex]\frac{3x+1}{2} - \frac{x-3}{4} = \frac{7}{4} - \frac{2x+5}{3}[/tex]
[tex]\frac{3x+1}{2} - \frac{x-3}{4} +\frac{2x+5}{3} = \frac{7}{4}[/tex] (am separat termenii)
[tex]\frac{6(3x+1)}{12} - \frac{3(x-3)}{12} + \frac{4(2x+5)}{12} = \frac{7}{4}[/tex] (am adus la același numitor membrul stâng)
[tex]\frac{18x+6 -3x+9+8x+20}{12} = \frac{7}{4}[/tex]
[tex]\frac{23x+35}{12} = \frac{7}{4}[/tex]
4(23x + 35) = 12·7 (produsul mezilor este egal cu produsul extremilor)
92x + 140 = 84
92x = -56
x = -56:92 = -14:23
