Classify the Linear Function: Understanding y=2-3x

Linear Functions with Negative Slopes

Which best describes the function below?

y=23x y=2-3x

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:05 Let's find out if the function goes up, goes down, or stays the same.
00:10 We start by using the equation of a straight line.
00:14 Next, let's rearrange the equation so it looks like a straight line equation.
00:19 Here, the coefficient of X gives us the slope of the graph.
00:26 The slope is negative, so the function is going down.
00:31 And that's how we solve this problem!

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

Which best describes the function below?

y=23x y=2-3x

2

Step-by-step solution

To determine the characteristic of the function y=23x y = 2 - 3x , we will evaluate the slope:

  • The given function is in the form y=mx+b y = mx + b , which indicates a linear equation. Here, y=23x y = 2 - 3x can be rearranged as y=3x+2 y = -3x + 2 , showing that m=3 m = -3 .
  • The slope m m is 3-3.
  • In a linear function, the sign of the slope m m determines the function's behavior:
    • If the slope m m is positive (m>0 m > 0 ), the function is increasing.
    • If the slope m m is negative (m<0 m < 0 ), the function is decreasing.
    • If the slope m=0 m = 0 , the function is constant.
  • Since m=3 m = -3 , which is negative, we conclude that the function is decreasing.

Therefore, the function described by y=23x y = 2 - 3x is decreasing.

3

Final Answer

The function is decreasing.

Key Points to Remember

Essential concepts to master this topic
  • Slope Rule: Negative slope means function decreases as x increases
  • Standard Form: Rewrite y=23x y = 2 - 3x as y=3x+2 y = -3x + 2
  • Check: Pick two x-values: when x increases, y decreases ✓

Common Mistakes

Avoid these frequent errors
  • Confusing coefficient order with slope sign
    Don't think y=23x y = 2 - 3x has positive slope because 2 comes first = wrong classification! The coefficient of x determines behavior, not the constant term. Always identify the slope by looking at the x coefficient: -3 means decreasing.

Practice Quiz

Test your knowledge with interactive questions

What is the solution to the following inequality?

\( 10x-4≤-3x-8 \)

FAQ

Everything you need to know about this question

How do I know if a linear function is increasing or decreasing?

+

Look at the slope (coefficient of x)! If it's positive, the function increases. If it's negative, the function decreases. In y=23x y = 2 - 3x , the slope is -3, so it's decreasing.

Why does the order of terms matter?

+

The order doesn't change the slope! Whether you write y=23x y = 2 - 3x or y=3x+2 y = -3x + 2 , the slope is still -3. Always focus on the coefficient of x to determine the function's behavior.

What does it mean for a function to be decreasing?

+

A decreasing function means as x gets larger, y gets smaller. Think of it like going downhill - as you move right on the graph, you go down!

Can I test this with actual numbers?

+

Absolutely! Try x = 0: y=23(0)=2 y = 2 - 3(0) = 2 . Try x = 1: y=23(1)=1 y = 2 - 3(1) = -1 . See how y went from 2 to -1? That's decreasing!

What if the slope was zero?

+

If the slope equals zero, like y=20x=2 y = 2 - 0x = 2 , then the function is constant. The y-value never changes no matter what x equals.

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Linear Functions questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations