Back
GED Math — Algebra
📈 Slope-Intercept Form & Line Equations
Read a graph · identify slope and y-intercept · complete the equation y = mx + b
Progress
0%
📐
y = mx + b Formula
m = slope, b = y-intercept
📏
Reading Slope
Rise ÷ Run from the graph
🎯
GED Problem
Line k: y = (p/r)x + 0, variables p, r, s
🖱️
Drag & Drop
Click tokens to fill the equation boxes
🧩
More Examples
Read a graph and write the equation
📝
Practice Quiz
8 GED-style slope & equation problems

💡 The GED Drag-and-Drop Format

The GED shows a graph of a line and asks you to drag the correct values (like p, r, and 0) into boxes to complete the equation y = ___x + ___. You must read the slope from the graph's rise and run labels, and identify the y-intercept from the labeled point. This lesson teaches exactly that!

Lesson 1 — Slope-Intercept Form: y = mx + b
Every straight line can be written in this form — know what each part means!
Slope-Intercept Form
y = mx + b
m = slope (steepness / direction)  |  b = y-intercept (where line crosses y-axis)
m — The Slope

How steep the line is.
Positive m → line goes up left to right ↗
Negative m → line goes down ↘
m = rise ÷ run

b — The Y-Intercept

Where the line crosses the y-axis (where x = 0).
If the line passes through (0, p), then b = p.
If it passes through the origin, b = 0.

Quick Reference Examples
EquationSlope (m)Y-intercept (b)
y = 2x + 323
y = −x + 5−15
y = (p/r)x + 0p/r0 (origin)
Lesson 2 — Reading Slope from a Graph
Slope = Rise ÷ Run — measured directly from the graph labels!
📌 The Slope Formula

Slope (m) = Rise ÷ Run

Rise = vertical change (up = positive, down = negative)
Run = horizontal change (right = positive, left = negative)

On the GED graph, the rise and run are often labeled directly with letters like s (side/run) and r (rise), or with arrows showing the vertical and horizontal distances.

Rise = s (vertical), Run = r (horizontal) → Slope = s/r
1
Pick two clear points on the line

Choose points where the line crosses grid intersections — easy to read exactly.

2
Count the rise (vertical change)

How many units up or down from the first point to the second? Up = positive.

3
Count the run (horizontal change)

How many units right or left from the first point to the second? Right = positive.

4
Divide: Slope = Rise ÷ Run

Write as a fraction if needed. Keep signs!

Lesson 3 — The Exact GED Problem
Line k passes through (0, p) and has rise labeled p and run labeled r. Complete the equation y = ___x + ___
Line k — y-intercept at (0, p), rise = p, run = r, label s on side
📋 Reading the Graph

Y-intercept: The line passes through (0, p) — so b = p... but wait! The graph shows the line going THROUGH the origin with a rise bracket labeled and s on the side. Let's analyze carefully.

✅ What the Labels Tell Us

p = the rise (vertical distance)
r = the run (horizontal distance)
s = an extra label on the side
Y-intercept (0, p) is labeled on the graph
→ Slope = p/r  |  Y-intercept = p... but (0,p) IS the y-intercept!

✅ GED Problem Answer — The Correct Equation
Slope
The slope = rise ÷ run = p ÷ r = p/r
So m = p/r → numerator box = p, denominator box = r
Y-int
The graph shows the line crosses the y-axis at the origin (0, 0) based on the diagram — so the y-intercept = 0
Result
Complete equation of line k:
y = (p/r)x + 0
Why Each Token Goes Where It Does
TokenWhere It GoesWhy
pNumerator of slopep = the vertical rise of the line
rDenominator of sloper = the horizontal run of the line
0Y-intercept box (+___)Line crosses y-axis at origin (0,0)
sNOT useds labels the side/slant — not part of the equation
🖱️ Interactive: Complete the Equation
Click a token below, then click a box to place it. Build the equation of line k!
The Graph — Line k
Use the rise, run, and y-intercept from the graph to fill in the equation boxes below.
Complete the equation of line k:
y =
?
?
x +
?
Available Tokens — click one to select, then click a box:
💡 Hint

Slope = rise ÷ run. The rise is labeled p and run is labeled r on the graph.
The y-intercept is where the line crosses the y-axis. Look at where x = 0 on the graph.

Lesson 5 — More Graph Reading Examples
Read slope and y-intercept from different line graphs!
Three different lines — each with a different slope and y-intercept
🔵 Line A — slope = 2, y-intercept = 1
Read
Rise = 2, Run = 1 → slope = 2/1 = 2. Crosses y-axis at (0, 1).
y = 2x + 1
🔴 Line B — slope = −1, y-intercept = 3
Read
Rise = −1 (going down), Run = 1 → slope = −1. Crosses y-axis at (0, 3).
y = −x + 3
🟢 Line C — slope = 1/2, y-intercept = 0
Read
Rise = 1, Run = 2 → slope = 1/2. Crosses y-axis at origin (0, 0). So b = 0.
y = (1/2)x + 0    or just    y = (1/2)x
GED Tips — Line Equations from Graphs
What to do when you see a graph with labeled variables!
💡
Slope = Rise ÷ Run — identify the labels

The GED graph labels the rise and run with letters. Rise goes in the numerator, run goes in the denominator.

💡
Y-intercept = where x = 0

Look for the labeled point on the y-axis. If it's (0, p), then b = p. If it's at the origin, b = 0.

💡
Not all tokens/variables are used

The GED provides more options than needed. Here, "s" is the label on the slant side of the right triangle — it's NOT used in the equation. Don't be distracted by extra labels!

💡
Positive vs. negative slope

If the line goes UP from left to right → positive slope. If it goes DOWN → negative slope. Line k goes up → slope is positive (p/r).

Line k Summary
ComponentValueWhere from Graph
Slope (m)p/rRise=p, Run=r labeled on right triangle
Y-intercept (b)0Line passes through origin
Equationy = (p/r)x + 0Complete slope-intercept form
Practice Quiz — Slope & Line Equations
8 GED-style problems on slope-intercept form!
Question 1 of 8
Score: 0 / 8
Insert math as
Block
Inline
Additional settings
Formula color
Text color
#333333
Type math using LaTeX
Preview
\({}\)
Nothing to preview
Insert