 If four quantities are in proportion, they are in proportion by composition; that is, the sum of the first two terms is to the second term as the sum of the last two terms is to the fourth term.  Second Course in Algebra - Page 210by Webster Wells, Walter Wilson Hart - 1913 - 342 pagesFull view - About this book
 | Webster Wells - Algebra - 1879 - 468 pages
...: d then, ad = b с Whence, b : a = d : c. 347. If four quantities are in proportion, they will be in proportion by COMPOSITION ; that is, the sum of the first two terms will be to the first term, as the sum of the last two terms is to the third term. Thus, if a : b =... | |
 | Webster Wells - 1885 - 368 pages
...as the fourth term is to the third. Let a : b = с : d. Then, ad — be. Whence, b : a = d : c. 299. In any proportion the terms are in proportion by....that is, the sum of the first two terms is to the first term, as the sum of the last two terms is to the third ter.n. Let a : b — с : d. Then, ad... | |
 | Webster Wells - Algebra - 1885 - 324 pages
...as the fourth term is to the third. Let a : & = с : d. Then, ad = be. Whence, b : a = d : c. 299. In any proportion the terms are in proportion by Composition...that is, the sum of the first two terms is to the first term, as the sum of the last tico terms is to the third term. Let a : b = с : d. Then, ad =... | |
 | Webster Wells - Algebra - 1885 - 370 pages
...as the fourth term is to the third. Let ч :l!:- r : d. Then, ad = be. Whence, b : a = d : c. 299. In any proportion the terms are in proportion by Composition...that is, the sum of the first two terms is to the first term, as the sum of the last two terms is to the third tern. Let a : b = с : d. Then, ad = be.... | |
 | Webster Wells - Geometry - 1886 - 392 pages
...: 6 = c : d. Then by §242, ad = bc. Whence by § 244, b : a = d : c. PROPOSITION V. THEOREM. 247. In any proportion the terms are in proportion by COMPOSITION...that is, the sum of the first two terms is to the first term as the sum of the last two terms is *<> the third term. Let a : 6 = c : d. Then, ad = be.... | |
 | Webster Wells - Algebra - 1889 - 584 pages
...as the fourth term is to the third. Let a : & = с : d. Then, aa = bc. Whence, b : a = d : c. 315. In any proportion the terms are in proportion by Composition...that is, the sum of the first two terms is to the first term, as the sum of the last two terms is to the third term. Let a : b = с : d. Then, ad = bc.... | |
 | Webster Wells - Algebra - 1890 - 604 pages
...as the fourth term is to the third. Let a : b = с : d. Then, ad = 6e. Whence, b : a = d : c. 387. In any proportion the terms are in proportion by Composition...that is, the sum of the first two terms is to the first term as the sum of the last two terms is to the third term. Let a : b = с : d. Then, ad = 6e.... | |
 | Edward Albert Bowser - Geometry - 1890 - 420 pages
...= be. (281) .-. a:c = b:d. (283) QED Proposition 5. 287. If four quantities are in proportion, they are in proportion by composition; that is, the sum of the first and second is to the second as the sum of the third and fourth is to the fourth. Hyp. Let a : b = c... | |
 | George W. Lilley - Algebra - 1892 - 420 pages
...= -j-~ Therefore, a + b :b :: c + d : d. Hence, VI. If four numbers are in proportion, they will be in proportion by composition; that is, the sum of the first two will be to the second as the sum of the last two is to the fourth. Let a : b : : с : d. ac By definition,... | |
 | Webster Wells - Geometry - 1894 - 394 pages
...= d:c. (§ 233.) PROPOSITION V. THEOREM. 236. In any proportion, the terms are in proportion £,t7 COMPOSITION ; that is, the sum of the first two terms is to the first term as the sum of the last two terms is to the third term. Let the proportion be a : b = c:... | |
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