To find the cost to border Gabrielle's garden, we can use the formula:
\[ \text{Cost} = 1.50 \times (2l + 2w) \]
where \( l \) is the length and \( w \) is the width of the garden.
Given:
- \( l = 4 \) yards
- \( w = 3 \) yards
First, we can calculate \( 2l + 2w \):
\[ 2l = 2 \times 4 = 8 \] \[ 2w = 2 \times 3 = 6 \]
Now add these values together:
\[ 2l + 2w = 8 + 6 = 14 \]
Next, substitute this value into the cost formula:
\[ \text{Cost} = 1.50 \times 14 \]
Now, calculate the cost:
\[ \text{Cost} = 21 \]
The total cost for the border around Gabrielle's garden is $21.00.