Question

How do you write the rational number 10.5 in the form a/b?
Can you please help me.

Answer 1

Answer: 21/2

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Work Shown:

10.5 = 10 + 0.5

10.5 = 10 + (1/2)

10.5 = (20/2) + (1/2)

10.5 = (20+1)/2

10.5 = 21/2

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Alternative Route:

10.5 = 10.5/1

10.5 = 105/10 <--- multiply top and bottom by 10

10.5 = (21*5)/(2*5)

10.5 = 21/2 <---- cancel the common factors