1. The problem asks to analyze the algebraic expression $3x + 4$ and answer four questions about it. 2. First, count the number of terms in $3x + 4$. A term is a part of the expression separated by plus or minus signs. Here, there are two terms: $3x$ and $4$. 3. Next, find the coefficient of the algebraic term. The algebraic term is $3x$, and its coefficient is the number multiplying the variable $x$, which is $3$. 4. Then, identify the constant term. The constant term is the term without a variable, which is $4$. 5. Finally, determine the operation symbol. The operation symbol between the two terms is $+$. 6. The second problem asks to evaluate the expression $2a - 3$ when $a = 5$. 7. Substitute $a = 5$ into the expression: $2(5) - 3$. 8. Calculate: $2 \times 5 = 10$, so the expression becomes $10 - 3$. 9. Subtract: $10 - 3 = 7$. 10. The value of the expression when $a = 5$ is $7$. 11. The third problem is to fill in the table for the expressions $x + 9$, $7x$, and $5x - 2$ for $x = 0$ and $x = 2$. 12. For $x = 0$: - $x + 9 = 0 + 9 = 9$ - $7x = 7 \times 0 = 0$ - $5x - 2 = 5 \times 0 - 2 = -2$ 13. For $x = 2$: - $x + 9 = 2 + 9 = 11$ - $7x = 7 \times 2 = 14$ - $5x - 2 = 5 \times 2 - 2 = 10 - 2 = 8$ Final answers: ① Number of terms: 2 ② Coefficient of algebraic term: 3 ③ Constant term: 4 ④ Operation symbol: $+$ ⑤ Table values: | x | x + 9 | 7x | 5x - 2 | |---|-------|----|--------| | 0 | 9 | 0 | -2 | | 2 | 11 | 14 | 8 |