Question

writing equations to represent a real - world system of linear equations
the volleyball team at west view high school is comparing t - shirt companies where they can purchase their practice shirts. the graph represents the two companies prices. what is the linear equation that represents each t - shirt company?
shirt box
just tees
$y = 5.5x$
$y = 10.5x$
$y = 6.5x + 30$
$y = 7.5x + 30$

Explanation:

Step1: Identify Shirt Box's intercept

Shirt Box has a y-intercept $b=30$ (when $x=0$, $y=30$).

Step2: Calculate Shirt Box's slope

Use point $(4,60)$: $m=\frac{60-30}{4-0}=\frac{30}{4}=7.5$

Step3: Write Shirt Box's equation

Substitute $m=7.5, b=30$ into $y=mx+b$:
$y=7.5x+30$

Step4: Calculate Just Tees's slope

Use point $(6,63)$, y-intercept $b=0$: $m=\frac{63-0}{6-0}=10.5$

Step5: Write Just Tees's equation

Substitute $m=10.5, b=0$ into $y=mx+b$:
$y=10.5x$

Answer:

Shirt Box: $y = 7.5x + 30$
Just Tees: $y = 10.5x$