Answer:
A)
![{2s + 5t = 49.50\\\\s = 2t](https://img.qammunity.org/2023/formulas/mathematics/high-school/mik5pnz96lbx1xtmztpco18abs477w2wu9.png)
B) Keegan paid $5.50 for each t-shirt and $11 for each short.
Explanation:
A)
⭐ What is a system of equations?
- A system of equations is two or more equations that intersect at a common point (x,y)
We are asked to create a system of equations for Keegan's situation.
Let s = the price for every short
Let t = the price for every t-shirt
So, if Keegan buys 2 shorts and 5 t-shirts, his cost will be $49.50.
As an equation, this situation would be:
![2s + 5t = 49.50](https://img.qammunity.org/2023/formulas/mathematics/high-school/jqa8yzcmsp7xnqorbj3dkish78v8xockqw.png)
It's given that the cost of 1 short is twice the cost of 1 t-shirt.
As an equation, this situation would be:
![s = 2t](https://img.qammunity.org/2023/formulas/mathematics/high-school/oiy7ggwvvvll19r89kdssg9vruk5ldcjc8.png)
B)
⭐How can we solve a system of equations?
- You can solve a system of equations by substitution
- You can solve a system of equations by graphing
- You can solve a system of equations by elimination
For this problem, the best way to solve this system of equations is through substitution. I will demonstrate how to use substitution for this problem.
Using the equations
and
, we will literally substitute a variable from one equation into another equation to solve for the other variable.
Given that
:
![2s + 5t = 49.50](https://img.qammunity.org/2023/formulas/mathematics/high-school/jqa8yzcmsp7xnqorbj3dkish78v8xockqw.png)
![2(2t) + 5t = 49.50](https://img.qammunity.org/2023/formulas/mathematics/high-school/jfyt3lnxwljbhprirzdvpm6mvnlvjbbs9w.png)
![4t + 5t = 49.50](https://img.qammunity.org/2023/formulas/mathematics/high-school/2m3xpcdcx27b9f9o85zb0i5w4ezlph572t.png)
![9t = 49.50](https://img.qammunity.org/2023/formulas/mathematics/high-school/7yshr7s0t9kxz42g3ugki54setdmdh655a.png)
![t = 5.50](https://img.qammunity.org/2023/formulas/mathematics/high-school/rxy7mv3wl023zyv0ujmqp1fizbjrwcixg4.png)
∴ It costs Keegan $5.50 for one t-shirt.
Now, we can substitute the value of t into the same equation to solve for the value of s.
Given that
:
![2s + 5(5.50) = 49.50](https://img.qammunity.org/2023/formulas/mathematics/high-school/rnkb3q9aoivu74oqtao5h8667n2ywwgloa.png)
![2s + 27.5 = 49.50](https://img.qammunity.org/2023/formulas/mathematics/high-school/xbbp7fqoa13y1p2u5n4za0od10142dma3g.png)
![2s = 22](https://img.qammunity.org/2023/formulas/mathematics/high-school/u55yf7z6zesad7hw0gmgr86qj8n4n5gkrk.png)
![s = 11](https://img.qammunity.org/2023/formulas/mathematics/high-school/swx498q1tngtbux5buw2j04e6piw7diwax.png)
∴ It costs Keegan $11 for one short.