[tex]a_1 = 3x-2\\a_2 = 4-x\\a_3 = 3x+5[/tex]
Z własności ciągu arytmetycznego:
[tex]a_2 = \frac{a_1+a_3}{2}\\\\4-x = \frac{3x-2+3x+5}{2}\\\\4-x = \frac{6x+3}{2} \ \ |\cdot2\\\\6x+3 = 8-2x\\\\6x+2x = 8-3\\\\8x = 5 \ \ /:7\\\\\boxed{x = \frac{5}{8}}[/tex]
[tex]a_1 = 3x-2 = 3\cdot\frac{5}{8}-2 = \frac{15}{8}-\frac{16}{8} =\boxed{ -\frac{1}{8}}\\\\a_2 = 4-x = 4-\frac{5}{8} = 3\frac{8}{8}-\frac{5}{8} = \boxed{3\frac{3}{8}}\\\\a_3 = 3x+5 = 3\cdot\frac{5}{8}+5 = \frac{15}{8}+5 = 1\frac{7}{8}+5 = \boxed{6\frac{7}{8}}[/tex]
