Let's solve each of these problems step by step. We are asked to write the
slope-intercept form of the equation of each line.
The
slope-intercept form is:
$$
y = mx + b
$$
Where:
- $ m $ is the
slope of the line,
- $ b $ is the
y-intercept (the point where the line crosses the y-axis).
We'll find $ m $ and $ b $ for each graph.
---
1) First Graph
Look at the line on the first grid.
#### Step 1: Find the y-intercept ($b$)
The line crosses the y-axis at $ y = 3 $. So,
$$
b = 3
$$
#### Step 2: Find the slope ($m$)
Use two points on the line. Let's pick:
- $ (-2, 4) $
- $ (0, 3) $
Now calculate the slope:
$$
m = \frac{y_2 - y_1}{x_2 - x_1} = \frac{3 - 4}{0 - (-2)} = \frac{-1}{2} = -\frac{1}{2}
$$
So the equation is:
$$
y = -\frac{1}{2}x + 3
$$
✔ Answer for #1: $ \boxed{y = -\frac{1}{2}x + 3} $
---
2) Second Graph
#### Step 1: Find the y-intercept ($b$)
The line crosses the y-axis at $ y = 2 $. So,
$$
b = 2
$$
#### Step 2: Find the slope ($m$)
Pick two points:
- $ (0, 2) $
- $ (2, 0) $
$$
m = \frac{0 - 2}{2 - 0} = \frac{-2}{2} = -1
$$
So the equation is:
$$
y = -x + 2
$$
✔ Answer for #2: $ \boxed{y = -x + 2} $
---
3) Third Graph
#### Step 1: Find the y-intercept ($b$)
The line crosses the y-axis at $ y = -1 $. So,
$$
b = -1
$$
#### Step 2: Find the slope ($m$)
Pick two points:
- $ (0, -1) $
- $ (1, 2) $
$$
m = \frac{2 - (-1)}{1 - 0} = \frac{3}{1} = 3
$$
So the equation is:
$$
y = 3x - 1
$$
✔ Answer for #3: $ \boxed{y = 3x - 1} $
---
4) Fourth Graph
#### Step 1: Find the y-intercept ($b$)
The line crosses the y-axis at $ y = -2 $. So,
$$
b = -2
$$
#### Step 2: Find the slope ($m$)
Pick two points:
- $ (0, -2) $
- $ (1, 1) $
$$
m = \frac{1 - (-2)}{1 - 0} = \frac{3}{1} = 3
$$
So the equation is:
$$
y = 3x - 2
$$
✔ Answer for #4: $ \boxed{y = 3x - 2} $
---
✔ Final Answers:
1) $ y = -\frac{1}{2}x + 3 $
2) $ y = -x + 2 $
3) $ y = 3x - 1 $
4) $ y = 3x - 2 $
Let me know if you'd like a visual explanation or help with any other problems!
Parent Tip: Review the logic above to help your child master the concept of writing linear equations in slope intercept form worksheet pdf.