Εικόνες σελίδας
PDF
Ηλεκτρ. έκδοση

of the rule under Art. 18, where a reverse operation was required to be performed.

EXAMPLES.

1. Reduce 13 to an improper fraction.

Multiplying the integer 13 by the denominator 7, we obtain 91; to which, adding the numerator 6, we get 97 for the numerator of the improper fraction; .. the improper fraction equivalent to 13 is 27.

2. What improper fraction is equivalent to 1278 ?

[blocks in formation]

3. What improper fraction is equivalent to 18910 ? Ans. 132874.

4. What improper fraction is equivalent to 4925361? Ans. 6402979.

1 3

[merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors]

4

7

20. Reduce the compound fraction of to its equivalent simple fraction.

of can be obtained by dividing the value of the

[ocr errors]

fraction by 4, which (by Prop. II., Art. 16,) can be effected by multiplying the denominator by 4;

[merged small][ocr errors][merged small][ocr errors][ocr errors][merged small]

Again, of is obviously three times as great as

4

of. to obtain of 7, we must multiply

[ocr errors][merged small]

by 3, which (by Prop. I., Art. 16,) can be done by

multiplying the numerator by 3; hence, we have

[blocks in formation]

91

of

4

Hence, to reduce compound fractions to their equivalent simple ones, we have this

RULE.

Consider the word of, which connects the fractional parts as equivalent to the sign of multiplication. Then multiply all the numerators together for a new numerator, and all the denominators together for a new denominator, always observing to reject or cancel such factors as are common to the numerators and denominators, which is the same as dividing both numerator and denominator by the same quantity, and (by Rule under Art. 17,) does not change the value of the fraction.

EXAMPLES.

12

1. Reduce of of of to its equivalent simple. 3 3 5 15 fraction.

Substituting the sign of multiplication for the word of, we get ××× First canceling the 8 of the

[ocr errors]

8

15

[ocr errors]

5

12

[ocr errors]

numerator against the 2 and 4 of the denominator, by

drawing a line across them, we get

1

[ocr errors]

3 $

X

5X

5

A 5 12

Again, canceling the 3 and 5 of the numerator against the 15 of the denominator, we finally obtain

[blocks in formation]

5

2. Reduce of 1 of 7 of of to its simplest

form.

3 5

[ocr errors]

First, canceling the 7 and 5 of the numerator against

3
7~35 8

147 4 $

the 35 of the denominator, we get XX

$$

Again, canceling the 7 of the denominator against a part of the 14 of the numerator, and the 3 of the numerator against a part of the 9 of the denominator, we obtain

[merged small][merged small][merged small][ocr errors][merged small][merged small]

Finally, canceling the 2 and 4 of the numerator against 8 of the denominator, we get

[merged small][merged small][ocr errors][ocr errors][ocr errors][merged small][merged small][merged small][merged small]

NOTE. We have written our fractions several times, in order the more clearly to exhibit the process of canceling. But in practice, it will not be necessary to write the fraction more than once. It will make no difference which of the factors are first canceled. When all the common factors have, in this way, been stricken out, the fraction will then appear in its lowest terms.

The student will find it to his interest to perform many examples of this kind, as this principle of canceling will be extensively employed in the succeeding parts of this work.

[ocr errors]

3. Reduce of of 28 of 333 to its simplest

form.

3 1 1

1 3

3

4.9

6 10

[blocks in formation]

4. Reduce of of 1 of 2 of 2 of of to its simplest form. Ans. 15. 5. Reduce of % of 13 of 14 of to its simplest form. Ans. T•

24

70

9

18

2 26 1

6. Reduce 1 of 2 of 7 of 33 to its simplest form. Ans. 62983.

2 3

0 5.

7. Reduce of of 3 of 52 of to its simplest form. Ans. 756.

8

8. Reduce of 2 of 3 of 4 of of of 7 of to its simplest form. Ans. 1.

9. Reduce of of 8 of 19 to its simplest form.

[blocks in formation]

10. Reduce of 1 of 1 of 3 to its simplest form.

[blocks in formation]

21. To reduce fractions to a common denominator, we have this

RULE.

Reduce mixed numbers to improper fractions-compound fractions to their simplest form. Then multiply each numerator by all the denominators, except its own, for a new numerator, and all the denominators together for a common denominator.

It is obvious that this process will give the same denominator to each fraction, viz: the product of all the denominators.

It is also obvious that the values of the fractions will not be changed, since both numerator and denominator

are multiplied by the same quantity, viz: the product of all the denominators except its own.

EXAMPLES.

[ocr errors]

1. Reduce,of,, and of, to equivalent fractions having a common denominator.

These fractions, when reduced to their simplest form, are,,, and .

[ocr errors]

The new numerator of the first fraction is 1 × 3 × 11 × 9=297.

The new numerator of the second fraction is 2×2× 11x9

396.

The new numerator of the third fraction is 3×2×3× 9=162.

The new numerator of the fourth fraction is 2×2×3 ×11=122.

The common denominator is 2×3×11×9=594. Therefore, the fractions, when reduced to a common

[blocks in formation]

337, 38, 162, and 132.
231, 334, 394,

5949

6

594

2. Reduce of 1,1 of 1, and 4, to equivalent

8

[ocr errors]

fractions having a common denominator.

2009 9 6

Ans. 88, 188, and 2218.

7

22961 2 2 9

4 0 9 6

3. Reduce, of 3, and 41, to equivalent frac

3 7

tions having a common denominator.

Ans. 117, 14%, and 1887.

6149 7667

8 0 4

7

8 0

0 4

4. Reduce, 11, 41, and 43 to equivalent fractions.

31 479

having a common denominator.

53

[merged small][subsumed][subsumed][ocr errors][subsumed][subsumed][subsumed]

5. Reduce 3, 3, and, to fractions having a com

[merged small][merged small][merged small][merged small][ocr errors]

6. Reduce, and 11, to fractions having a com

[merged small][merged small][merged small][merged small][merged small][ocr errors]
« ΠροηγούμενηΣυνέχεια »