Answer:
Grass sod: $9
Ornamental grass: $11
Step-by-step explanation:
In order to solve this we first have to set a term for each Grass sod and ornamental grass, we will use X and Y for each one:
Grass sod: X
Ornamental grass: Y
So we create two equations:
14x + 14y=280
12x+13y=251
We can solve this system of ecuations by elimination:
![12(14x + 14y=280)=168x+168y=3360\\-14(12x+13y=251)= -168x-182y=-3514\\-14y=-154\\y=11](https://img.qammunity.org/2020/formulas/chemistry/high-school/oejdr4tedf8xfol6k2v5ryskzybxkj7ts5.png)
Now we just inser the value of Y into anyone of the two equations:
![14x + 14y=280\\14x+ 14(11)=280\\14x+154=280\\14x=280-144\\14x=126\\x=(126)/(14) \\x=9](https://img.qammunity.org/2020/formulas/chemistry/high-school/xfx5nq0u3d6dtqjz9rhnlwdppx2jua90rw.png)
So we know that the grass rod costs 9 dollars and the ornamental grass 11