Algebra Class: Key Equations and Concepts
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Algebra Class: Key Equations and Concepts

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@DistinctiveDrama

Questions and Answers

Solve −4(2x − 1) = −6(x + 2) − 2.

9

Rearrange the formula C = 2πr to solve for r.

r = C/2π

Solve −2x − 13 = 8x + 7.

-2

Solve 4x − 9 = 15.

<p>6</p> Signup and view all the answers

Given the equation 3x − 3 = 6x + 1, select the reasoning that correctly solves for x.

<p>Subtract 1, subtract 3x, then divide by 3.</p> Signup and view all the answers

Solve x/4 = 8.

<p>32</p> Signup and view all the answers

Solve −5x = 30.

<p>-6</p> Signup and view all the answers

In order to solve the equation −3x + 6 = 5, what is the first step?

<p>Subtract 6 from both sides.</p> Signup and view all the answers

Let f(x) = x^2 − 3x − 7. Find f(−3).

<p>11</p> Signup and view all the answers

Let f(x) = 5x + 12. Find f^−1(x).

<p>x - 12/5</p> Signup and view all the answers

Let f(x) = 12/4 x + 2. Find f(−1).

<p>-6</p> Signup and view all the answers

Let f(x) = 9x − 2 and g(x) = −x + 3. Find f(g(x)).

<p>-9x + 25</p> Signup and view all the answers

Let f(x) = x − 2 and g(x) = x^2 − 7x − 9. Find f(g(−1)).

<p>-3</p> Signup and view all the answers

Let f(x) = 2x − 6. Solve f^−1(x) when x = 2.

<p>4</p> Signup and view all the answers

On the graph of the equation x - 4y = -16, what is the value of the y-intercept?

<p>4</p> Signup and view all the answers

For the functions f(x) = 2x + 2 and g(x) = 7x + 1, which composition produces the greatest output?

<p>g(f(x)) produces the greatest output.</p> Signup and view all the answers

Which of the following expressions represents a function: {(1, 2), (4, -2), (8, 3), (9, -3)}?

<p>True</p> Signup and view all the answers

Consider the function f(x) = 8 − 3x^2. Find the value of f(x) when x = 3.

<p>-19</p> Signup and view all the answers

Given the function f(x) = 3x + 4, which of the following expressions is the inverse?

<p>y = (x - 4)/3</p> Signup and view all the answers

A.Given the equation 2(3x − 4) = 5x + 6, solve for the variable. What is Charlie's solution?

<p>Charlie is incorrect. His answer should be x = 1/2.</p> Signup and view all the answers

If the linear function representing the amount of rainfall each week is f(w) = 2.5w + 3, what does the 3 represent in this function?

<p>The amount of rainfall in week 0</p> Signup and view all the answers

What type of line is the graph of 4x + y = −3?

<p>Falling</p> Signup and view all the answers

What is the slope of the line between (3, −4) and (−2, 1)?

<p>-1</p> Signup and view all the answers

What is the slope of the line y = 3?

<p>0</p> Signup and view all the answers

What is the slope of the line between (-4, 4) and (-1, -2)?

<p>-2</p> Signup and view all the answers

What is the slope of the line that passes through (2, 12) and (4, 20)?

<p>4</p> Signup and view all the answers

What is the equation of a horizontal line passing through the point (−7, 5)?

<p>y = 5</p> Signup and view all the answers

Given the equation 4x − 26 = 2x − 4, what order of operations completely solves for x?

<p>Subtract 2x, then add 26, lastly divide by 2.</p> Signup and view all the answers

Which function has the largest slope?

<p>g(x)</p> Signup and view all the answers

Given that f(x) = 2x + 1 and g(x) = −5x + 2, solve for f(g(x)) when x = 3.

<p>-25</p> Signup and view all the answers

Study Notes

Key Equations and Concepts

  • Circumference of a Circle: C = 2πr; rearranged to solve for radius: r = C/2π.
  • Common Linear Equation Forms:
    • Slope-Intercept Form: y = mx + b, where m is the slope and b is the y-intercept.
    • Point-Slope Form: y - y1 = m(x - x1), used when a point and slope are known.

Solving Linear Equations

  • Typical solving strategy: isolate the variable through addition, subtraction, multiplication, or division.
  • Example: -4(2x − 1) = −6(x + 2) − 2 results in x = 9.
  • Example: From -2x − 13 = 8x + 7, deduced x = -2.

Functions and Their Inverses

  • For a function f(x) = ax + b, the inverse process involves swapping x and y, leading to f^−1(x).
  • Example: f(x) = 2x + 2; solving f^−1(x) gives x = 4.
  • Composition of functions: f(g(x)) requires evaluating the outer function at the result of the inner function.

Graphing and Slopes

  • Slope Calculation: The slope between two points (x1, y1) and (x2, y2) is m = (y2 - y1) / (x2 - x1).
  • Example: Slope between (3, -4) and (-2, 1) is -1.
  • Horizontal line has a slope of 0; vertical line is undefined.

Linear Models in Context

  • Example: A function representing rainfall f(w) = 2.5w + 3 indicates that 3 is the baseline rainfall before week 1.
  • Example: Alex saves money modeled by M = 6h + 2, denoting initial savings and rate of saving.

Errors and Reasoning in Problem Solving

  • Identifying mistakes in calculations is crucial. Example: Aaron erred by subtracting incorrectly in solving the equation.
  • Understanding the order of operations and justifying each step is essential for accurate results.

Special Function Characteristics

  • Functions like f(x) = x^2 + 3x + 6 can yield specific outputs for given x-values through substitution.
  • Ensure that the range for practical functions, such as the number of text messages sent, only includes integers.

Application Problems

  • Real-world problems, like Joe's earnings model, combine fixed rates and variable conditions to derive total outcomes.
  • A fish tank model (F = 0.4P) helps quantify relationships between variables such as fish count and plant presence.

Visual Characteristics of Graphs

  • A falling line indicates a negative slope, such as x = -5, which is a vertical line.
  • The y-intercept is often determined by substituting x = 0 in the equation.

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Description

Test your knowledge on key algebraic equations, including the circumference of a circle and linear equations in different forms. The quiz also covers solving linear equations, functions and their inverses, as well as graphing techniques. Ideal for reinforcing your understanding of essential algebra concepts.

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