| 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, —... | |
| 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
...5. The sum 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
...may be 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...and 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... | |
| Arithmetic - 1817 - 214 pages
...difference, and to the product add the first term, the sum is the last term. > 2. Multiply the sum ef the two **extremes by the number of terms, and half the product will be the** sum of all the terms. EXAMPLES. 1 . The first term of a certain series in arithmetical pro gression... | |
| Arithmetic - 1818 - 264 pages
...5. The sum of all the terms. PROBLEM I. The first term, the last term, and the number of terms being **given, to find the sum of all the terms. RULE. Multiply...and half the product will be the answer. EXAMPLES.** 1. The first term of an arithmetical progression is 5, the last term, 60, and the number of terms 12,... | |
| |