A series with same common difference is known as arithmetic series. The first term of series is \'a\' and common difference is d. The series looks like a, a + d, a + 2d, a + 3d, . . . Find the sum of series.具有相同共同差异的系列被称为算术系列。系列的第一个术语是“ a ”，共同的区别是d。该系列看起来像a + d，a + 2d，a + 3d...找到系列的总和。