To determine which of the given sums results in a rational number according to the Closure Property, let's analyze each option:
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0.643892553... + 34
- 0.643892553... is a decimal expansion that does not terminate or repeat, so it is an irrational number. However, adding a rational number (34) to an irrational number will still yield an irrational number. Result: Irrational
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√36 + √221
- √36 is 6, which is rational. √221 is an irrational number. The sum of a rational number and an irrational number is irrational. Result: Irrational
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0.6 + 9/10
- Here, 0.6 (or 6/10) is a rational number (it can be expressed as 3/5) and 9/10 is also a rational number. The sum of two rational numbers is rational. Result: Rational
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π + √4
- π is an irrational number and √4 is 2, which is rational. The sum of a rational number and an irrational number is irrational. Result: Irrational
Based on the analysis, the only sum that results in a rational number is:
0.6 + 9/10.