identity the rational no which are in standard from also convert where ration number into standard form? question is 3/-7
Answers
Step-by-step explanation:
What is the standard form of a rational number?
A rational number ab is said to be in the standard form if b is positive, and the integers a and b have no common divisor other than 1.
How to convert a rational number into standard form?
In order to express a given rational number in the standard form, we follow the following steps:
Step I: Obtain the rational number.
Step II: See whether the denominator of the rational number is positive or not. If it is negative, multiply or divide numerator and denominator both by -1 so that denominator becomes positive.
Step III: Find the greatest common divisor (GCD) of the absolute values of the numerator and the denominator.
Step IV: Divide the numerator and denominator of the given rational number by the GCD (HCF) obtained in step III. The rational number so obtained is the standard form of the given rational number.
The following examples will illustrate the above procedure to convert a rational number into standard form.
1. Express each of the following rational numbers in the standard form:
(i) −924 (ii) −14−35 (iii) 27−72 (iv) −55−99
Solution:
(i) −924
The denominator of the rational number −924 is positive. In order to express it in standard form, we divide its numerator and denominator by the greatest common divisor of 9 and 24 is 3.
Dividing the numerator and denominator of −924 by 3, we get
−924 = (−9)÷324÷3 = −38
Thus, the standard form of −924 is −38.
(ii) −14−35
The denominator of the rational number −14−35 is negative. So, we first make it positive.
Multiplying the numerator and denominator of −14−35 by -1 we get
−14−35 = (−14)×(−1)(−35)×(−1) = 1435
The greatest common divisor of 14 and 35 is 7.
Dividing the numerator and denominator of 1435 by 7, we get
1435 = 14÷735÷7 = 25
Hence, the standard form of a rational number −14−35 is 25.
(iii) 27−72
The denominator of 27−72 is negative. So, we first make it positive.
Multiplying the numerator and denominator of 27−72 by -1, we have
27−72 = 27×(−1)(−72)×(−1) = −2772
The greatest common divisor of 27 and 72 is 9.
Dividing the numerator and denominator of −2772 by 9, we get
−2772 = (−27)÷972÷9 = −38
Hence, the standard form of 27−72 is −38.
(iv) −55−99
The denominator of −55−99 is negative. So, we first make it positive.
Multiplying the numerator and denominator of −55−99 by -1, we have
−55−99 = (−55)×(−1)(−99)×(−1)= 5599
The greatest common divisor of 55 and 99 is 11.
Dividing the numerator and denominator of by 5599 by 11, we get
5599 = 55÷1199÷11 = 59
Hence, the standard form of −55−99 is 59.
More examples on standard form of a rational number:
2. Express the rational number −247−228 in the standard form:
Solution:
The denominator of −247−228 is negative. So, we first make it positive.
Multiplying the numerator and denominator of −247−228 by -1, we get
−247−228 = (−247)×(−1)(−228)×(−1) = 247228
Now, we find the greatest common divisor of 247 and 228.
247 = 13 × 19 and 228 = 2 × 2 × 3 × 19
Clearly, the greatest common divisor of 228 and 247 is equal to 19.
Dividing the numerator and denominator of 247228 by 19, we get
247228 = 247÷19228÷19 = 13/12
Hence, the standard form of −247−228 is 1312.
3. Express the rational number 299−161 in the standard form:
Solution:
The denominator of 299−161 is negative. So we first make it positive.
Multiplying the numerator and denominator of 299−161 by -1, we get
299−161 = 299×(−1)(−161)×(−1) = −299161
Now, we find the greatest common divisor of 299 and 161:
299 = 13 × 23 and 161 = 7 × 23
Clearly, the greatest common divisor of 299 and 161 is equal to 23.
Dividing the numerator and denominator of −299161
by 23 we get
−299161 = (−299)÷23161÷23 = −137
Hence, the standard form of a rational number 299−161 is −137.