9/8 - 18/5 as a fraction

Learn how to find what is 9/8 minus 18/5 in fraction form just in a few minutes. We have covered the easiest method to write 9/8 - 18/5 as a fraction and decimal.

Summary: 9/8 minus 18/5 = -99/40
Since both fractions have unequal denominators, 9/8 minus 18/5 is an unlike fractions subtraction. For subtracting unlike fractions, you have to first find the equivalent fractions for fraction 9/8 and fraction 18/5 in order to have the same denominators for both fractions. Therefore, you have to find the LCM of denominators 8 and 5. 40 is the LCM of 8 and 5. Multiplying the LCM 40 with the numerators and denominators of both fractions (9/8 x 40/40) - (18/5 x 40/40), and simplify further in order to have the common denominator. So the equivalent fraction for 9/8 is 45/40 and for 18/5 is 144/40. By simplifying this fraction subtraction 45/40 - 144/40, it becomes -99/40.

CALCULATION: 9/8 - 18/5 as a fraction
9/8 - 18/5 = (?)
9/8 - 18/5 = [(9 x 5) - (18 x 8)]/(8 x 5)
= (45 - 144)/40
= -99/40
9/8 - 18/5 = -99/40
9/8 minus 18/5 as a fraction is -99/40.

where
9/8 is a improper fraction as a minuend,
18/5 is a improper fraction as a subtrahend,
-99/40 is the difference between 9/8 and 18/5.

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9/8 minus 18/5 as a decimal
9/8 - 18/5 = -99/40
-99/40 = -2.475
(9/8) - (18/5) as a decimal is -2.475

where
-2.475 is the difference between 9/8 and 18/5.

The below workout with step by step calculation shows how to find what is the difference between two fractions by subtracting a fraction 18/5 from 9/8. For different, unequal or unlike denominators, use any one of the following methods to find the equivalent fraction for 9/8 minus 18/5.
1. LCM method
2. Cross multiplication method.

(9/8) - (18/5) using LCM Method:
What is 9/8 minus 18/5 as a fraction?

step 1 Observe the input parameters and what to be found:
Input:
Fraction A: 9/8
Fraction B: 18/5

What to be found?
(9/8) - (18/5) = ?
Find what's the difference between 9/8 and 18/5.

step 2 Compare the denominators of fractions 9/8 and 18/5 to identify whether it is a like or unlike fraction subtraction. Since the denominators of given fractions 9/8 and 18/5 are not equal, it is said to be unlike fractions subtraction.

step 3For unlike fractions subtraction, find the LCM (least common multiple) of both denominators of fractions 9/8 and 18/5:
The LCM of 8 and 5 is 40.

step 4 Write the fractions 9/8 and 18/5 in the subtraction expression form and multiply LCM with all the numerators and denominators of both fractions.
= 9/8 - 18/5
= [(9 x 40)/(8 x 40)] - [(18 x 40)/(5 x 40)]

step 5 Simplify the expression to have common denominator:
= 45/40 - 144/40

step 6 Take the common values out and rewrite the above expression like the below:
= 1/40 x (45/1 - 144/1)
= 1/40 x (45 - 144)

step 7Simplify the above expression further:
= 1/40 x -99
= -99/40
9/8 - 18/5 = -99/40

Hence,
9/8 minus 18/5 as a fraction is -99/40.

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9/8 - 18/5 using Cross Multiplication Method:
step 1 Observe the input parameters and what to be found:
Input:
Fraction A: 9/8
Fraction B: 18/5

What to be found?
(9/8)-(18/5) = ?
Find what's the difference between 9/8 and 18/5.

step 2 Find the product of numerator of Fraction A and denominator of Fraction B (9 x 5), find the product of numerator of Fraction B and denominator of Fraction A (18 x 8), and find the product of both denominators of Fraction A and Fraction B (8 x 5) and rewrite the equation as like the below:
= (9 x 5) - (18 x 8)/(8 x 5)

step 3 Simplify and rewrite the fraction:
= (45 - 144)/40
9/8 - 18/5 = -99/40

Hence,
9/8 minus 18/5 in fraction is -99/40