Write and Solve Equations Using Addition or Subtraction
Name Period
Objectives / Objetivos
Content Objective: I can solve one-step addition and subtraction equations using inverse operations.
Language Objective: I can explain my steps using the words equation, inverse operation, isolate, and solution.
Key Idea / Idea clave
Solving Addition & Subtraction Equations. Formula: x + a = b → x = b − a | x − a = b → x = b + a. 1. Identify operation on variable. 2. Use inverse operation: subtract to undo addition; add to undo subtraction. 3. Property of Equality: do same operation to both sides.
I Notice / Observo
- What operation connects the locker number and 23?
- What does n represent in the equation?
I Wonder / Me pregunto
- What if the message said 'the number minus 23 equals 58' instead?
Vocabulary / Vocabulario
| Term / Término | Definition / Definición |
|---|---|
| Solve One-Step Addition and Subtraction Equations Resolver ecuaciones de suma y resta de un paso | Use one inverse addition or subtraction operation to isolate the variable. Usar una operación inversa de suma o resta para aislar la variable. |
| Equation Ecuación | A math sentence with an equal sign showing both sides are the same. Una oración matemática con un signo igual que muestra que ambos lados son iguales. |
| Inverse operation Operación inversa | Two math actions that undo each other, like × and ÷. Dos operaciones que se deshacen entre sí, como × y ÷. |
| Isolate Despejar | To get the letter by itself on one side. Dejar la letra sola en un lado. |
| Solution Solución | A number that makes the equation or inequality true. Un número que hace verdadera la ecuación o desigualdad. |
| One-step equation Ecuación de un paso | An equation you can solve in a single step using one inverse operation. Una ecuación que puedes resolver en un solo paso usando una operación inversa. |
Practice Preview / Vista previa de práctica
Read each task. Show your work in the spaces provided and explain how you know.
1. Solve: x + 9 = 15
- A x = 6
- B x = 9
- C x = 15
- D x = 24
Answer:
2. Solve: m − 14 = 32
m − 14 = 32
3. Complete the table: identify the inverse operation, solve, and check.
Complete each empty cell. Show your reasoning below.
| Equation | Inverse Operation | Solution | Check |
|---|---|---|---|
| x + 18 = 45 | |||
| p − 22 = 19 | |||
| w + 3.5 = 10 |
4. Find the Equation Error
Which step has the mistake, and what should it be?
Reflection / Reflexión
One thing I learned today / Una cosa que aprendí hoy: