We are given four tables, each showing a linear relationship between two variables. For each, we must write a
linear equation that defines the
dependent variable in terms of the
independent variable.
A linear equation has the form:
>
y = mx + b
where:
- `y` is the dependent variable,
- `x` is the independent variable,
- `m` is the slope (rate of change),
- `b` is the y-intercept (value of y when x = 0).
---
Problem 1: Define p in terms of k
Table:
```
k | p
0 | 16
3 | 15
6 | 14
9 | 13
```
- Independent variable: `k`
- Dependent variable: `p`
Step 1: Find the slope (m)
Use any two points. Let’s use (0, 16) and (3, 15):
> m = (change in p) / (change in k) = (15 - 16) / (3 - 0) = (-1)/3 =
-1/3
Step 2: Find the y-intercept (b)
When k = 0, p = 16 → so
b = 16
✔ Equation: p = (-1/3)k + 16
---
Problem 2: Define s in terms of p
Table:
```
p | s
0 | 3
1 | 5
2 | 7
3 | 9
```
- Independent variable: `p`
- Dependent variable: `s`
Step 1: Find slope (m)
Use (0, 3) and (1, 5):
> m = (5 - 3)/(1 - 0) = 2/1 =
2
Step 2: Find y-intercept (b)
When p = 0, s = 3 →
b = 3
✔ Equation: s = 2p + 3
---
Problem 3: Define d in terms of a
Table:
```
a | d
0 | 0
4 | 5
8 | 10
12| 15
```
- Independent variable: `a`
- Dependent variable: `d`
Step 1: Find slope (m)
Use (0, 0) and (4, 5):
> m = (5 - 0)/(4 - 0) = 5/4
Step 2: Find y-intercept (b)
When a = 0, d = 0 →
b = 0
✔ Equation: d = (5/4)a
*(You can also write it as d = 1.25a)*
---
Problem 4: Define k in terms of c
Table:
```
c | k
0 | 17
4 | 14
8 | 11
12| 8
```
- Independent variable: `c`
- Dependent variable: `k`
Step 1: Find slope (m)
Use (0, 17) and (4, 14):
> m = (14 - 17)/(4 - 0) = (-3)/4 =
-3/4
Step 2: Find y-intercept (b)
When c = 0, k = 17 →
b = 17
✔ Equation: k = (-3/4)c + 17
---
##
✔ Final Answers:
1.
p = -⅓k + 16
2.
s = 2p + 3
3.
d = ⁵⁄₄a
4.
k = -¾c + 17
These equations correctly model the linear relationships shown in each table.
Parent Tip: Review the logic above to help your child master the concept of writing linear equations from tables worksheet.