Gabrielle wants to put a border around her garden. It costs $1.50 per yard for the materials. Use 1.50(2l+2w)

To find the cost of the border for Gabrielle's garden using the formula \( 1.50(2l + 2w) \), we first need to plug in the values for the length (\( l \)) and width (\( w \)) of the garden.

Given:
- Length (\( l \)) = 4 yards
- Width (\( w \)) = 3 yards

Substituting these values into the formula:

\[
1.50(2l + 2w) = 1.50(2(4) + 2(3))
\]

Calculating inside the parentheses:

\[
2(4) = 8
\]
\[
2(3) = 6
\]

Now add these results:

\[
2l + 2w = 8 + 6 = 14
\]

Now substitute this back into the formula:

\[
1.50(14)
\]

Now calculate the cost:

\[
1.50 \times 14 = 21
\]

So, the cost for the border around Gabrielle's garden is **$21.00**.