Answer:
Cost of a fern = $4
cost of a rose bush = $3
Explanation:
Let cost of a fern in dollars be =
![x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/k3ozza40nv61jy1offmxaxutrb6y1c3ly5.png)
Let cost of a rosebush in dollars be =
![y](https://img.qammunity.org/2020/formulas/mathematics/college/uw0b7dbqmfpakodpw1nh8u5h9nrcutx8vw.png)
Matt purchased 8 ferns and 1 rosebush for $35
Cost of 8 ferns in dollars will be =
![8x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dl1tsvp6ozj0p1pvqkwub4x3g00qidl21k.png)
cost of a rosebush in dollars is =
![y](https://img.qammunity.org/2020/formulas/mathematics/college/uw0b7dbqmfpakodpw1nh8u5h9nrcutx8vw.png)
Total cost of 8 ferns and 1 rosebush in dollars =
![8x+y](https://img.qammunity.org/2020/formulas/mathematics/college/nvlyapm6ds7fy9vq07mq79q4i474a9voku.png)
So, we have a Matt's equation as:
![8x+y=35](https://img.qammunity.org/2020/formulas/mathematics/college/ay669tm5qc0uk1udtvlo77f4abh861jabq.png)
Trey purchased 4 ferns and 3 rosebushes for $25.
Cost of 4 ferns in dollars =
![4x](https://img.qammunity.org/2020/formulas/mathematics/high-school/mn8feglp5shfkjwjpn7fx7q0hz2xwiqh4j.png)
Cost of 3 rosebushes in dollars =
![3y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/65pdne0z2fb3as0pdpqbjir6atejs8texf.png)
Total cost of 4 ferns and 3 rosebush in dollars =
![4x+3y](https://img.qammunity.org/2020/formulas/mathematics/college/bldbxww0j5npv3g8imbe491eyzlhxsj01d.png)
So, we have a Trey's equation as:
![4x+3y=25](https://img.qammunity.org/2020/formulas/mathematics/college/qygg7aarlkby1y556fmn4cbtn59440x6vf.png)
The system of equations is :
A)
![8x+y=35](https://img.qammunity.org/2020/formulas/mathematics/college/ay669tm5qc0uk1udtvlo77f4abh861jabq.png)
B)
![4x+3y=25](https://img.qammunity.org/2020/formulas/mathematics/college/qygg7aarlkby1y556fmn4cbtn59440x6vf.png)
Solving the system by substitution method.
Rearranging equation A, to solve for
in terms of
![x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/k3ozza40nv61jy1offmxaxutrb6y1c3ly5.png)
Subtracting both sides by
![8x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dl1tsvp6ozj0p1pvqkwub4x3g00qidl21k.png)
![8x+y-8x=35-8x](https://img.qammunity.org/2020/formulas/mathematics/college/xhofexfzd4ldor9co0cn68iyojelcfp9d4.png)
![y=35-8x](https://img.qammunity.org/2020/formulas/mathematics/college/iipkux2amsgoqp8f49j12l9b3044ag76k8.png)
Substituting value of
we got from A into equation B.
![4x+3(35-8x)=25](https://img.qammunity.org/2020/formulas/mathematics/college/ai9rfmzsx5rritlheww8lecs6r2ycajj7d.png)
Using distribution.
![4x+105-24x=25](https://img.qammunity.org/2020/formulas/mathematics/college/kpaapj5dor0wms5kl40me0eba8ctv3vv5b.png)
Simplifying.
![-20x+105=25](https://img.qammunity.org/2020/formulas/mathematics/college/7ygfaq9ilt82gcuxpt833f7w500ofqmjpt.png)
Subtracting both sides by 105.
![-20x+105-105=25-105](https://img.qammunity.org/2020/formulas/mathematics/college/x94rxrbxzr2c98dfqf1px831c6f23wk1x3.png)
![-20x=-80](https://img.qammunity.org/2020/formulas/mathematics/college/2o4gx35dt2r2ut2w3kgbaxf2s2vors9grl.png)
Dividing both sides by -20.
![(-20x)/(-20)=(-80)/(-20)](https://img.qammunity.org/2020/formulas/mathematics/college/unmmg8b3o9yi9hy0lnkd0w1cpogardoa7i.png)
∴
![x=4](https://img.qammunity.org/2020/formulas/mathematics/high-school/hxnxycp7ditjozikbfiiya3nb2g21vrzay.png)
We can plugin
in the rearranged equation A to get value of
![y](https://img.qammunity.org/2020/formulas/mathematics/college/uw0b7dbqmfpakodpw1nh8u5h9nrcutx8vw.png)
![y=35-8(4)](https://img.qammunity.org/2020/formulas/mathematics/college/gt6h17od6n5peeszvski52o0d4j0w6rs42.png)
![y=35-32](https://img.qammunity.org/2020/formulas/mathematics/college/qs8nmkapfuuxkhubbf7xc1yica0ue4qu6f.png)
∴
![y=3](https://img.qammunity.org/2020/formulas/mathematics/high-school/bz4oxcswmw3r7gvwn866nuoh3alxt85uy3.png)
Cost of a fern = $4
Cost of a rosebush = $3