| Benjamin Greenleaf - Arithmetic - 1858 - 458 pages
...the sum of the series must equal half the sum of the extremes multiplied by the number of terms, or **the sum of the extremes multiplied by half the number of terms.** RULE. — Multiply half the sum of the extremes by the number of terms. Or, Multiply the sum of the... | |
| Benjamin Greenleaf - Arithmetic - 1858 - 456 pages
...the sum of the series must equal half the sum of the extremes multiplied by the number of terms, or **the sum of the extremes multiplied by half the number of terms.** RULE. — Multiply half the sum of the extremes l»j the number of terms. Or, Multiply the sum of the... | |
| Charles Davies - Algebra - 1860 - 332 pages
...Here, (a+l) is taken n times ; hence, 2s = n(a+l) ; or, s — %n(a+T) . . (2.) That is, the sum of the **terms is equal to the sum of the extremes, multiplied by half the number of terms.** Formula ( 2 ) can be placed under another form, by substituting for I its value taken from Formula... | |
| Charles Davies - Arithmetic - 1863 - 346 pages
...and 19, taken as many times as there are terms; and the given series is equal to half this sum, or **to the sum of the extremes multiplied by half the number of terms.** Rule. — Add the extremes together, and multiply their sum by half the number of terms ; the product... | |
| Henry William Jeans - 1873 - 292 pages
...reduce arithmetical and algebraical expressions to logarithms* (22). (a) The logarithm of the product **of any number of terms is equal to the sum of the** logarithms of all the terms in the product : Thus, if x=ab, then log. a:=log. a + log. b (b) The logarithm... | |
| William Guy Peck - Algebra - 1875 - 348 pages
...(a + 1) is taken n times ; hence, 2s = n(a + 1); or, s = %n(a + I), . . (2) that is, the sum of the **terms is equal to the sum of the extremes, multiplied by half the number of terms.** Formula (2) can be placed under another form, by substituting for I its value taken from formula (1):... | |
| Indiana. State Board of Education - 1886 - 360 pages
...4 25 7 22 10 19 13 10 16 13 19 10 22 7 25 4 It follows, therefore, that the sum of a series equals **the sum of the extremes multiplied by half the number of terms.** 7. If the first term of a decreasing series is 100 and the common difference 3, what is the 32d term... | |
| Charles Davies - Algebra - 1889 - 330 pages
...Here, (a+l) is taken n times; hence, 2s = n(a+l); or, s = $n(a + l) . . (2.) That is, the sum of the **terms is equal to the sum of the extremes, multiplied by half the number of** term*. Formula ( 2 ) can be placed under another form, by substituting for I its value taken from Formula... | |
| Marshall Clagett - History - 1989 - 494 pages
...stated in the following rule: In any geometrical progression whose first term is equal to the ratio, **the sum of any number of terms is equal to the sum of** one less number of terms plus 1 multiplied by the ratio. This rule the author follows in the first... | |
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