Question:
Write the following rational numbers in the descending order.
(8/7), (-9/8), (-3/2), 0, (2/5)
Solution:
The LCM of the denominators 7, 8, 2 and 5 is 280
∴ 8/7 = [(8×40)/ (7×40)] = (320/280)
(-9/8) = [(-9×35)/ (8×35)] = (-315/280)
(-3/2) = [(-3×140)/ (2×140)] = (-420/280)
(2/5) = [(2×56)/ (56×56)] = (112/280)
Now, 320 > 112 > 0 > -315 > -420
Hence, ⇒ 8/7 > 2/5 > 0 > -9/8 > -3/2
Descending order 8/7, 2/5, 0, -9/8, -3/2