Answer:
Where y is the cost and x is the number of skeins of yarn.
Step-by-step explanation:
To model this situation we can use the linear equation:
Where y is the cost, x is the number of skeins of yarn, a is the slope of the equation and b is the y-intercept.
If 2 skeins of yarn cost $7, we have that:
If 8 skeins of yarn cost $28, we have that:
Multiplying the first equation by 4 and subtracting the second equation from it, we have:
Now, finding the value of a, we have:
So our equation is: