Question

this graph shows how the number of spools of thread that amy has left is related to the number of shirts that she sews. if amy sews 5 shirts, how many spools of thread will she have left? 10 spools of thread 60 spools of thread 40 spools of thread 50 spools of thread

Explanation:

Step1: Find slope of the line

First, identify two points on the line: when shirts sewn $x_1=0$, remaining spools $y_1=60$; when $x_2=10$, $y_2=20$.
Slope $m=\frac{y_2-y_1}{x_2-x_1}=\frac{20-60}{10-0}=\frac{-40}{10}=-4$

Step2: Write linear equation

Use y-intercept form $y=mx+b$, where $b=60$ (y-intercept).
Equation: $y=-4x+60$

Step3: Calculate for x=5 shirts

Substitute $x=5$ into the equation.
$y=-4(5)+60=-20+60=40$

Answer:

40 spools of thread