 | Alexander Malcolm - Algebra - 1730 - 702 pages
...fliewn that</x«— -i=s/— -л. and dividing equally by » — i, it is</= *. Ж *^~ I 2. For ti multiply the Sum of the Extremes by the Number of Terms, and take half of the Produo, it's the Sum : Thus *= *"HX*. E*a*,fk: - = 3./=iy.» = 7. then is /==6, —... | |
 | Mathematics - 1801 - 446 pages
...the terms. . , PROBLEM I. , 1'te frit term, the last term, and the number of terms behtg given, to find the sum of all the terms. RULE.* Multiply the...and half the product will be the answer. EXAMPLES. * Suppose another series of the same kind with the given one be placed under it in an inverse order... | |
 | Samuel Webber - Mathematics - 1808 - 466 pages
...Thejirst term, the last term, and the number of terms beinggiven, to jind the sum of all the terms, Multiply the sum of the extremes by the number of...half the product will be the answer. EXAMPLES. 1. The first term of an arithmetical progrrssion is 2, the last term 53, and the number of terms 18 ;... | |
 | Nicolas Pike - Algebra - 1808 - 470 pages
...term, the last term, and the number of terms being given, tojind the sum of all the terms. RuLE.f — Multiply the sum of the extremes by the number of terms, and half the producl will be the answer. EXAMPLES. • The difference of the firft and laft terms evidently (hews... | |
 | Nicolas Pike - Arithmetic - 1809 - 312 pages
...term, and the number of terms being gi-oent to fnd the fum of all ths terms, RULE. Multiply the fum of the extremes by the number of terms, and half the product will be the anfwer. EXAMPLES. i. The extremes of an arithmetical feries are 3 and 39, and the number of terms i... | |
 | Arithmetic - 1811 - 210 pages
...difference, and ,to the product add the first teim, the sum is the last term. 2. Multiply the sum of the two extremes by the number of terms, and half the product will be the sum qf all the terms. f EXAMPLES. •I. The first term 01 a certain series in anumicucoi progression... | |
 | Samuel Webber - Arithmetic - 1812 - 260 pages
...of all the terms. PR0BLEM 1. Tke first term, the last term, and the number of terms being given, to find the sum of all the terms. RULE.* / Multiply the sum of the extremes by the number of terms, ami half the product will be die vinswer. EXAMPLES. 1. The first term of an Arithmetical Progression... | |
 | Jeremiah Joyce - Arithmetic - 1812 - 274 pages
...easily found. I. When the first term a, and the last .term z, and th« number of terms n, are given, to find the sum of all the terms, *. RULE. Multiply the sum of the extremes by the number ofte/mi, and divide by 2, the quotient is the ansu-er: or n a. + z X — = s. Ex. i . What is the sum... | |
 | Nathan Daboll - Arithmetic - 1815 - 250 pages
...Problems ; but mast of them are best understood by an algebraic process, iand »re here omiti.".' t RULE. Multiply the sum of the extremes by the number of terms, and half the product wiH be the answer. EXAMPLE8. ). The first term of an arithmetical series is 3, the last term 23, and... | |
 | Nathan Daboll - Arithmetic - 1817 - 252 pages
...of Problems ; but most of them. are best understood by an algebraic process, md are here omitted. :, RULE. Multiply the sum of the extremes by the number...half the product will be the answer. EXAMPLES. 1. The first term of an arithmetical series is 3, the last term 23, and the number of terms 11 ; required... | |
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... the terms, RULE. Multiply the sum of the extremes by the number of terms, and half the product will be the sum of the terms. 
