expressions and equations unit test grade 7

📚 Quick Study Guide

• 🔢 Variables: Symbols (like $x$ or $y$) that represent unknown numbers.
• ➕ Expressions: Combinations of numbers, variables, and operations (like $3x + 5$).
• ➖ Equations: Mathematical statements that show two expressions are equal (like $2x + 1 = 7$). They have an equals sign (=).
• ⚖️ Solving Equations: Finding the value of the variable that makes the equation true. Use inverse operations (addition/subtraction, multiplication/division) to isolate the variable.
• ➗ Inverse Operations: Operations that undo each other. For example, subtraction is the inverse of addition, and division is the inverse of multiplication.
• 💡 Combining Like Terms: Simplify expressions by combining terms with the same variable and exponent (e.g., $3x + 2x = 5x$).
• 📝 Distributive Property: Multiplying a number by a sum or difference: $a(b + c) = ab + ac$.

Practice Quiz

1. Which of the following is an expression?
   1. A. $2x + 5 = 11$
   2. B. $3y - 7$
   3. C. $a + b = c$
   4. D. $8 = 8$
2. Solve for $x$: $x + 5 = 12$
   1. A. $x = 17$
   2. B. $x = 60$
   3. C. $x = 7$
   4. D. $x = 8$
3. Simplify the expression: $4a + 2a - a$
   1. A. $5a$
   2. B. $6a$
   3. C. $7a$
   4. D. $a$
4. Which property is illustrated by the equation: $3(x + 2) = 3x + 6$?
   1. A. Commutative Property
   2. B. Associative Property
   3. C. Distributive Property
   4. D. Identity Property
5. Solve for $y$: $2y - 4 = 8$
   1. A. $y = 2$
   2. B. $y = 4$
   3. C. $y = 6$
   4. D. $y = 12$
6. Combine like terms: $5x + 3y - 2x + y$
   1. A. $3x + 4y$
   2. B. $7x + 4y$
   3. C. $3x + 2y$
   4. D. $7x + 2y$
7. What is the value of the expression $3x - 5$ when $x = 4$?
   1. A. $12$
   2. B. $7$
   3. C. $17$
   4. D. $-7$