Examples with solutions for Variation of a Function: Calculate the rate of change from an equation

Exercise #1

For the following straight line equation, state what is the rate of change?

y=5x+4 y=5x+4

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Understand the equation format
  • Step 2: Identify the slope from the equation
  • Step 3: Match the slope to the given choices

Now, let's work through each step:
Step 1: The equation y=5x+4 y = 5x + 4 is in the slope-intercept form y=mx+b y = mx + b , where m m is the slope.
Step 2: From the equation, the slope m m is the coefficient of x x , which is 5. This represents the rate of change for this line.
Step 3: Among the choices, the correct choice representing the rate of change is 5.

Therefore, the solution to the problem is 5 5

Answer

5

Exercise #2

For the following straight line equation, state what is the rate of change?

y=8x3 y=8x-3

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Recognize the standard form of a linear equation.
  • Step 2: Identify the coefficient of x x as the rate of change.

Now, let's work through each step.
Step 1: Recognize that the given equation y=8x3 y = 8x - 3 is in the slope-intercept form y=mx+b y = mx + b , where m m is the slope.
Step 2: In this equation, the coefficient of x x is 8. Therefore, the coefficient 8 8 represents the rate of change or the slope of the line.

Thus, the rate of change for the equation y=8x3 y = 8x - 3 is 8 8 , which corresponds to choice 1.

Answer

8 8

Exercise #3

For the following straight line equation, state what is the rate of change?

y=4x+3 y=-4x+3

Video Solution

Step-by-Step Solution

To solve this problem, we need to determine the rate of change of the linear equation given by:

y=4x+3 y = -4x + 3

The standard form for a linear equation is:

y=mx+b y = mx + b

where m m represents the slope of the line. The slope indicates the rate of change of the function, which describes how much the value of y y changes for a unit change in x x .

In the equation y=4x+3 y = -4x + 3 , the slope m m is 4-4. This means that for every unit increase in x x , the value of y y decreases by 4. Thus, the rate of change for this equation is 4-4.

Therefore, the rate of change is 4 -4 .

Answer

4 -4

Exercise #4

For the following straight line equation, state what is the rate of change?

y=14x+8 y=\frac{1}{4}x+8

Video Solution

Step-by-Step Solution

To determine the rate of change for the given line equation y=14x+8 y = \frac{1}{4}x + 8 :

  • The equation is in the slope-intercept form, y=mx+b y = mx + b , where m m represents the slope or the rate of change.
  • By comparing the given equation y=14x+8 y = \frac{1}{4}x + 8 with the general form y=mx+b y = mx + b , we see that the slope m m is 14 \frac{1}{4} .
  • The rate of change for this line, thus, is 14\frac{1}{4}.

Therefore, the rate of change for the line is 14 \frac{1}{4} .

Answer

14 \frac{1}{4}

Exercise #5

For the following straight line equation, state what is the rate of change?

y=384x y=-\frac{3}{8}-4x

Video Solution

Step-by-Step Solution

To determine the rate of change for the given line equation, we recognize that the equation y=384x y = -\frac{3}{8} - 4x is in the slope-intercept form y=mx+b y = mx + b , where m m is the slope and represents the rate of change.

In the equation provided, the term 4x -4x indicates that the slope or rate of change is m=4 m = -4 .

Thus, the rate of change of the given straight line is 4 -4 .

Comparing this to the provided choices, the correct answer is:

  • Choice id "2": 4 -4

Therefore, the rate of change for the linear equation is 4 -4 .

Answer

4 -4

Exercise #6

For the following straight line equation, state what is the rate of change?

5x+y=3 -5x+y=3

Video Solution

Step-by-Step Solution

To solve this problem, let's follow these steps:

  • Step 1: Convert the given equation to the slope-intercept form.
  • Step 2: Identify the slope as the rate of change.

Now, let's work through each step:

Step 1: Convert to Slope-Intercept Form
The given equation is 5x+y=3 -5x + y = 3 . To convert it to the slope-intercept form, solve for y y :

Add 5x 5x to both sides to isolate y y :

y=5x+3 y = 5x + 3

Here, the equation is now in the form y=mx+b y = mx + b , where m m represents the slope.

Step 2: Identify the Slope
From the equation y=5x+3 y = 5x + 3 , we can see that the slope m m is 5 5 .

Therefore, the rate of change for the given line equation is 5 5 .

Answer

5 5

Exercise #7

For the following straight line equation, state what is the rate of change?

3y=14x 3-y=\frac{1}{4}x

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow the approach of rewriting the equation in slope-intercept form:

  • Step 1: Arrange the equation to isolate y y .
  • Step 2: Identify the coefficient of x x as the slope.
  • Step 3: Match the slope with the provided choices.

Let's work through these steps:
Step 1: Start with the original equation 3y=14x 3-y=\frac{1}{4}x . To solve for y y , add y y to both sides:
3=14x+y 3 = \frac{1}{4}x + y .
Subtract 14x \frac{1}{4}x from both sides to isolate y y :
y=14x+3 y = -\frac{1}{4}x + 3 .
Step 2: In the equation y=14x+3 y = -\frac{1}{4}x + 3 , the coefficient of x x is 14-\frac{1}{4}, which represents the slope or rate of change.
Step 3: Compare the calculated slope 14-\frac{1}{4} with the given choices. Choice 2, 14-\frac{1}{4}, is correct.

Therefore, the rate of change for the given line equation is 14 -\frac{1}{4} .

Answer

14 -\frac{1}{4}

Exercise #8

For the following straight line equation, state what is the rate of change?

8y+2x=6 -8y+2x=6

Video Solution

Step-by-Step Solution

To determine the rate of change for the given equation 8y+2x=6-8y + 2x = 6, follow these steps:

  • Step 1: Rearrange the equation to isolate yy. Start by subtracting 2x2x from both sides:
    8y=2x+6-8y = -2x + 6.
  • Step 2: Solve for yy by dividing every term by 8-8 to get yy by itself:
    y=28x+68y = \frac{-2}{-8}x + \frac{6}{-8}.
  • Step 3: Simplify the fractions:
    y=14x34y = \frac{1}{4}x - \frac{3}{4}.

In the equation y=14x34y = \frac{1}{4}x - \frac{3}{4}, the coefficient of xx is 14\frac{1}{4}, which represents the rate of change (slope) of the line. Therefore, the rate of change is 14\frac{1}{4}.

Answer

14 \frac{1}{4}

Exercise #9

For the following straight line equation, state what is the rate of change?

14y+x=3 -\frac{1}{4}y+x=3

Video Solution

Step-by-Step Solution

To solve this problem, let's convert the given equation into the standard slope-intercept form, y=mx+by = mx + b, to find the rate of change:

  • Step 1: Start with the equation 14y+x=3-\frac{1}{4}y + x = 3.
  • Step 2: Rearrange the equation to solve for yy. Subtract xx from both sides to get 14y=x+3-\frac{1}{4}y = -x + 3.
  • Step 3: Multiply every term by 4-4 to isolate yy. This gives us y=4x12y = 4x - 12.

Now that the equation is in the form y=mx+by = mx + b, the slope mm is the coefficient of xx, which is 44.

Therefore, the rate of change for the given straight line equation is 44.

Answer

4 4

Exercise #10

For the following straight line equation, state what is the rate of change?

x+y=0 -x+y=0

Video Solution

Step-by-Step Solution

To solve this problem, we need to determine the rate of change of the given line equation x+y=0-x + y = 0.

Let's proceed step-by-step:

  • Step 1: Identify the given equation, which is x+y=0-x + y = 0.
  • Step 2: Rearrange the equation to fit the slope-intercept form y=mx+by = mx + b.
    To do this, add xx to both sides:
    y=xy = x
  • Step 3: Identify the slope mm.
    In the equation y=xy = x, the term xx has a coefficient of 11, which means the slope m=1m = 1.
  • Step 4: Interpret the result.
    The slope 11 is the rate of change of the line, meaning for every unit increase in xx, yy increases by 1 unit.

Therefore, the rate of change of the line is 1 1 .

Answer

1 1