Answer:
![\left \{ {{0.2h+0.1s=2} \atop {h+s=15}} \right.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/tc4uwh6hycc1d4enguhbevk3593c59czck.png)
Explanation:
According to the exercise, we know that:
: Number of hats Chevy makes.
: number of scarves Chevy makes,
He wants to use 2 kilograms of yarn.
Knowing that each hat uses 0.2 kilograms of yarn and each scarf uses 0.1 kilograms of yarn, we can write the following equation to represent this situation:
Since Chevy wants to make 15 items in total, we can write this equation:
![h+s=15](https://img.qammunity.org/2020/formulas/mathematics/middle-school/6p9c2qsgpznkro518dp7tzgu474hjju0f4.png)
Finally, having these equations, we can set up the following system of equations that represents this situation:
![\left \{ {{0.2h+0.1s=2} \atop {h+s=15}} \right.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/tc4uwh6hycc1d4enguhbevk3593c59czck.png)
To solve it we can use the Substitutition Method. The steps are:
1. Solve for "s" from the second equation:
![s=15-h](https://img.qammunity.org/2020/formulas/mathematics/middle-school/g81jb0sekoc78cgnkym8cadsoqlsb1ouwx.png)
2. Substitute the equation above into the first equation and solve for "h":
![0.2h+0.1(15-h)=2\\\\0.2h+1.5-0.1h=2\\\\0.1h=2-1.5\\\\h=(0.5)/(0.1)\\\\h=5](https://img.qammunity.org/2020/formulas/mathematics/middle-school/92eo0925m4npeviglx7xzekt12k8bp67px.png)
3. Substitute the value of "h" into
to find the value of "s". Then:
![s=15-5\\\\s=10](https://img.qammunity.org/2020/formulas/mathematics/middle-school/74qs2xt31uzmaryizsm1715tazy0dooepy.png)