$\"\"$

The word “subtracted” indicates the symbol “ $\"\"$ ”.

The word “is” indicates the symbol “=”

Let n represents number. $\"\"$

Rewrite the sentence into equation, \ \

$\"\"$

The equation is n $\"\"$ 21 = 8 \ \

According to addition property of equality: if a = b, then a + c = b + c.

n $\"\"$ 21 + 21 = 8 + 21 (Add 21 to each side)

n = 8 + 21 (Additive inverse property: $\"\"$ 21 + 21 = 0)

n = 29 (Add: 8 + 21 = 29 \ \

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Check:

To check the solution, substitute n = 29 in original equation.

n $\"\"$ 21 = 8 $\"\"$ 29 $\"\"$ 21 = 8

8 = 8 (Subtract: 29 $\"\"$ 21 = 8)

Compare the values, the equation is true. The solution is n = 29.

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The value of n = 29.