 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.  Solid Geometry - Page 254by John H. Williams, Kenneth P. Williams - 1916 - 162 pagesFull view - About this book
 | Webster Wells, Walter Wilson Hart - Geometry - 1916 - 490 pages
...Ex. 21. Write the proportion -=-, by inversion, and then write by 255. In any proportion, the terms are in proportion by Composition ; that is, the sum of the first tiro terms is to the second, as the sum of the last two terms is to the fourth. If « = f, then £±*... | |
 | Elmer Adelbert Lyman, Albertus Darnell - Algebra - 1917 - 520 pages
....-Í-2eí-2I — or - = — . In 5 10 5 10 general this may be stated as follows : VI. If four numbers are in proportion, they are in proportion by composition...is, the sum of the first two terms is to the second as the sum of the last two terms is to the fourth. Or the sum of the first two terms is to the first... | |
 | Claude Irwin Palmer - Geometry, Solid - 1918 - 192 pages
...the fourth. § 406. Theorem. If four numbers form a proportion, they are in proportion by addition; that is, the sum of the first two terms is to the second as the sum of the last two terms is to the fourth. § 407. Theorem. If four numbers form a proportion,... | |
 | Claude Irwin Palmer, Daniel Pomeroy Taylor - Geometry - 1918 - 460 pages
...§398 .-•-A 406. Theorem. If four numbers form a proportion, they are in proportion by addition; that is, the sum of the first two terms is to the second as the sum of the last two terms is to the fourth. _. ac Given r = -. od .. a+b c+d To prove — =... | |
 | Arthur Schultze, Frank Louis Sevenoak - Geometry - 1918 - 486 pages
...Transform the proposition, m:x=p:q, so that x becomes the fourth term. PROPOSITION VI. THEOREM 283. If four quantities are in proportion, they are in proportion by composition, ie the sum of the first two terms is to the second term as the sum of the last two terms is to the... | |
 | Julius Lederer Neufeld - Algebra - 1920 - 412 pages
...If a:b = c:d Then be = ad Dividing by ac, - = u C or b : a = d : c Principle 5. — If four numbers are in proportion, they are in proportion by composition, that is, the sum of the terms of the first ratio is to either term of the first ratio as the sum of the terms of the second... | |
 | Arthur Schultze, Frank Louis Sevenoak - Geometry - 1913 - 484 pages
...Transform the proposition, m: x = p : q, so that x becomes the fourth term. PROPOSITION VI. THEOREM 283. If four quantities are in proportion, they are in proportion by composition, ie the sum of the first two terms is to the second term as the sum of the last two terms is to the... | |
 | Julius J. H. Hayn - Geometry, Plane - 1925 - 328 pages
...the form of a proportion, this becomes b : a = d : c. (See 189.) QED Proposition VI. Theorem 194. // 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.: Given a : b... | |
 | Edward Ira Edgerton, Perry Amherst Carpenter - Algebra - 1925 - 398 pages
...d, then b : a = d : c. 3. If four quantities are in proportion, they are in proportion by addition, that is, the sum of the first two terms is to the first term (or second) as the sum of the last two terms is to the third (or fourth). Ex., if a : b... | |
 | William Weller Strader, Lawrence D. Rhoads - Geometry, Plane - 1927 - 434 pages
...— ? Proposition 10 274. Theorem. Four quantities in proportion are in proportion also by addition; that is, the sum of the first two terms is to the second as the sum of the last two is to the fourth. Given: a : b = c : d. To prove: Proof: 1. b = d' О __... | |
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