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1. Find the value of the expression [tex]21 - 2a[/tex] if [tex]a = 3[/tex].

A. 57
B. 15
C. 27
D. 16

Sagot :

To find the value of the expression [tex]\(21 - 2a\)[/tex] when [tex]\(a = 3\)[/tex], follow these steps:

1. Substitute [tex]\(a = 3\)[/tex] into the expression:
[tex]\[ 21 - 2a \rightarrow 21 - 2(3) \][/tex]

2. Multiply [tex]\(2\)[/tex] by [tex]\(3\)[/tex]:
[tex]\[ 2 \times 3 = 6 \][/tex]

3. Subtract [tex]\(6\)[/tex] from [tex]\(21\)[/tex]:
[tex]\[ 21 - 6 = 15 \][/tex]

Therefore, the value of the expression [tex]\(21 - 2a\)[/tex] when [tex]\(a = 3\)[/tex] is [tex]\(15\)[/tex].

So, the correct answer is:
B. 15