 | Andrew Bell (writer on mathematics.) - 1839 - 500 pages
...(и — 1) 6f, which is 8 equal to a + z (424.) 1 The sum of the ternis of an equidifferent series is equal to the sum of the first and last terms multiplied by half the number of terms.1 For arranging the series in order, and also in a reverse order, as in the preceding theorem,... | |
 | Thomas Tate (mathematical master.) - 1847 - 138 pages
...in the given series. .'. 2s =7x14; .'. s=7J^!! = 49. m This result shows that the sum of the series is equal to the sum of the first and last terms multiplied by half the number of terms. In general let it be required to find the sum of the series, s= a + (a + d) + (a + 2d)+ ... to n terms.... | |
 | W. Hipsley - Business mathematics - 1852 - 116 pages
...multiplied by one less than the number of terms." " The sum of the terms of an equidifferent series is equal to the sum of the first and last terms, multiplied by half the number of terms." First term £20 Last term 20 + 4 44 2^ half the number of terms. 88 22 £110 sum of five terms. As... | |
 | W. Hipsley - 1852 - 122 pages
...multiplied by one less than the number of terms." " The sum of the terms of an equidifferent se'ies is equal to the sum of the first and last terms, multiplied by half the number of terms." First term £20 Last term 20 + 4 44 : 2^ half the number of terms. 88 22 £110 sum of five terms. As... | |
 | William Frederick Greenfield - 1853 - 228 pages
...the sum of two identical series, is twice the sum of one of them. Hence twice the sum of the series is equal to the sum of the first and last terms multiplied by the number of terms : or the sum of an Arithmetic series is the sum of the first and last terms multiplied... | |
 | James William M'Gauley - 1854 - 284 pages
...is called the greater extreme. EQUIDIFFERENT PROGRESSION. 55. The sum of an equidifferent series h equal to the sum of the first and last terms, multiplied by half the number of terms. For, it is equal to all the terms, added together. That is, a, being the lesser extreme ; b, the common... | |
 | Noble Heath - 1855 - 468 pages
...of any two corresponding terms of the series. The sum, therefore, of all the terms of both series, is equal to the sum of the first and last terms multiplied by the number of terms in one series ; and as this product is evidently just twice the sum of the terms... | |
 | Noble Heath - Arithmetic - 1856 - 472 pages
...of any two corresponding terms of the series. The sum, therefore, of all the terms of both series, is equal to the sum of the first and last terms multiplied by the number of terms in one series ; and as this product is evidently just twice the sum of the terms... | |
 | Barnard Smith - 1857 - 748 pages
...a+b 26. (na-6) + (nl)a+l(-2)« + 6} + &c. to n terms. hence it appears "that the sum of a series in Arithmetical Progression is equal to the sum of the first and last terms, multiplied into half the number of terms." Ex. 5. Find the 36"1 term of the series 40, 38, 36, &c., and the sum... | |
 | Chambers W. and R., ltd - 1859 - 344 pages
...number of terms 24. Required the lost term, Ans. 13. TlIE SUM OF THE TERMS OF AS EQUIDIFFERENT SERIES is equal to the sum of the first and last terms multiplied by half the number of terms. Take any equidifferent series, as 3, 7, 11, 15, 19, 23, consisting of any number of terms, as 6 ; then... | |
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