Sure, let's systematically identify the variable in each given algebraic expression.
1. [tex]\(4y + 12\)[/tex]: The variable in this expression is [tex]\(y\)[/tex].
2. [tex]\(k - 6\)[/tex]: The variable in this expression is [tex]\(k\)[/tex].
3. [tex]\(2x + 7\)[/tex]: The variable in this expression is [tex]\(x\)[/tex].
4. [tex]\(7n\)[/tex]: The variable in this expression is [tex]\(n\)[/tex].
5. [tex]\(\frac{2m}{4}\)[/tex]: The variable in this expression is [tex]\(m\)[/tex].
6. [tex]\(3(d)\)[/tex]: The variable in this expression is [tex]\(d\)[/tex].
7. [tex]\(\frac{\pi}{4}\)[/tex]: This expression contains no variable. None.
8. [tex]\(14k - 10\)[/tex]: The variable in this expression is [tex]\(k\)[/tex].
9. [tex]\(x - 100\)[/tex]: The variable in this expression is [tex]\(x\)[/tex].
10. [tex]\(3 \div p\)[/tex]: The variable in this expression is [tex]\(p\)[/tex].
11. [tex]\(4 + y\)[/tex]: The variable in this expression is [tex]\(y\)[/tex].
12. [tex]\(2m \div 5\)[/tex]: The variable in this expression is [tex]\(m\)[/tex].
So, summarizing:
1. y
2. k
3. x
4. n
5. m
6. d
7. None
8. k
9. x
10. p
11. y
12. m
