Answer:
[tex]18\frac{3}{4}[/tex] pounds.
Step-by-step explanation:
Let x be the total amount of potting soil needed to complete the planting in new garden.
We are told that a school group is helping plant a new city garden. Today they used 12 1/2 pounds of potting soil and planted 2/5 of the garden. This means 2/5 of x equals to 12 1/2.
[tex]\frac{2}{5} x=12\frac{1}{2}[/tex]
[tex]\frac{2}{5} x=\frac{25}{2}[/tex]
[tex]x=\frac{25}{2}\times\frac{5}{2}[/tex]
[tex]x=\frac{125}{4}[/tex]
To find the amount of soil needed for the next of planting we will subtract the amount of potting soil used on the first day [tex](\frac{25}{2})[/tex] from amount of total potting soil [tex](\frac{125}{4})[/tex].
[tex]\text{Amount of potting soil needed for second day}=\frac{125}{4}-\frac{25}{2}[/tex]
[tex]\text{Amount of potting soil needed for second day}=\frac{125}{4}-\frac{25\times 2}{2\times2}[/tex]
[tex]\text{Amount of potting soil needed for second day}=\frac{125}{4}-\frac{50}{4}[/tex]
[tex]\text{Amount of potting soil needed for second day}=\frac{75}{4}[/tex]
[tex]\text{Amount of potting soil needed for second day}=\frac{75}{4}=18\frac{3}{4}[/tex]
Therefore, the group will need [tex]18\frac{3}{4}[/tex] pounds of potting soil to finish their work.