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15 Flashcards in this deck.
One-step equations are the simplest form of algebraic equations, requiring only a single operation to solve for the unknown variable. These equations typically involve either addition or subtraction to isolate the variable on one side of the equation. Mastery of one-step equations is crucial as it lays the groundwork for tackling more intricate mathematical problems.
An equation consists of two expressions separated by an equals sign ($=$). The goal is to find the value of the variable that makes the equation true. In one-step equations involving addition or subtraction, the process involves performing the inverse operation to both sides of the equation to isolate the variable.
When dealing with addition equations, the objective is to eliminate the added constant to solve for the variable. This is accomplished by performing the inverse operation, which is subtraction.
**Example:** Solve for $x$ in the equation:
$$x + 5 = 12$$To isolate $x$, subtract $5$ from both sides:
$$x + 5 - 5 = 12 - 5$$ $$x = 7$$Thus, the solution is $x = 7$.
In subtraction equations, the goal is to eliminate the subtracted constant by adding the same value to both sides of the equation.
**Example:** Solve for $x$ in the equation:
$$x - 3 = 10$$To isolate $x$, add $3$ to both sides:
$$x - 3 + 3 = 10 + 3$$ $$x = 13$$Therefore, the solution is $x = 13$.
Verification ensures that the obtained solution satisfies the original equation. Substitute the value of $x$ back into the equation to confirm its validity.
**Verification Example:**
Given the equation $x + 5 = 12$ and the solution $x = 7$:
$$7 + 5 = 12$$ $$12 = 12$$The equality holds true, confirming that $x = 7$ is the correct solution.
One-step equations are not just abstract concepts; they have real-world applications. From calculating expenses and budgeting to determining distances and time, these equations help in making informed decisions based on mathematical reasoning.
**Example:** If a ticket to a movie costs $x$ dollars and you have $20$ dollars, how much more money do you need to buy 3 tickets?
$$3x = 20$$
Solving for $x$:
$$x = \frac{20}{3}$$ $$x \approx 6.67$$Each ticket costs approximately $6.67 dollars.
**Example 1: Addition
Solve for $y$:
$$y + 8 = 15$$Solution:
$$y = 15 - 8$$ $$y = 7$$**Example 2: Subtraction
Solve for $z$:
$$z - 4 = 9$$Solution:
$$z = 9 + 4$$ $$z = 13$$Word problems often require translating a real-life scenario into a mathematical equation. Identify the unknowns, define variables, and set up the equation accordingly.
**Example:** Sarah has $x$ apples. She buys 5 more apples and now has 12 apples. How many apples did Sarah have initially?
Equation Setup:
$$x + 5 = 12$$Solving:
$$x = 12 - 5$$ $$x = 7$$Sarah initially had 7 apples.
Mastering one-step equations equips students with the foundational skills necessary for higher-level mathematics, including two-step equations, systems of equations, and algebraic expressions. It fosters critical thinking and enhances problem-solving capabilities essential for academic and real-world challenges.
Aspect | Addition Equations | Subtraction Equations |
---|---|---|
Operation | Addition | Subtraction |
Inverse Operation | Subtraction | Addition |
Example Equation | $x + 7 = 14$ | $x - 3 = 10$ |
Solution Method | Subtract $7$ from both sides | Add $3$ to both sides |
Solution | $x = 7$ | $x = 13$ |
To efficiently solve one-step equations during exams, always first isolate the variable by performing the inverse operation. A useful mnemonic is "Inverse Isolate" – first identify the operation affecting the variable, then apply its inverse to isolate it. Practice with flashcards or online quizzes can reinforce these concepts, ensuring quick and accurate solutions under exam conditions.
One-step equations have been used in various fields beyond mathematics, including computer science and engineering. For instance, basic programming algorithms often rely on simple algebraic equations to perform calculations. Additionally, understanding these equations can help decode patterns in nature, such as the growth rates of populations or the decay of radioactive substances.
Students often make errors in selecting the correct inverse operation. For example, in solving $x + 4 = 10$, some might mistakenly add $4$ instead of subtracting, leading to $x = 14$. Correct approach: subtract $4$ from both sides to get $x = 6$. Another common mistake is forgetting to perform the inverse operation on both sides of the equation, which disrupts the balance and results in incorrect solutions.