Explicație pas cu pas:
a)
[tex]3x - 15 = 6 \\ 3x = 6 + 15 \\ 3x = 21 \\ x = \frac{21}{3} \\ x = 7[/tex]
b)
[tex]4x - 13 = 0 \\ 4x = 13 \\ x = \frac{13}{4} [/tex]
=> x ∈ ∅
c)
[tex] \frac{2}{5} x + 1 = 3.5 \\ \frac{2x}{5} = 3.5 - 1 \\ \frac{2x}{5} = \frac{25}{10} \\ x = \frac{5 \times 25}{2 \times 10} \\ x = \frac{25}{4} [/tex]
d)
[tex]4(x + 3) = 2x - 17 \\ 4x + 12 = 2x - 17 \\4x - 2x = - 17 - 12 \\ 2x = - 29 \\ x = - \frac{29}{2} [/tex]
=> x ∈ ∅
