There is another equation to solve it simultaneously
<em>Answer:</em>
<em>$0.38 per yard</em>
<em>Step-by-step explanation:</em>
<em>Step 1:</em>
Given; A 9-yard roll of string that costs $3.42.
Required; To find the unit price
<em> Step 2:</em>
Convert $3.42 to cents

<em>Step 3:</em>
<em>Find the unit price</em>




<em>Convert to dollars</em>


Hence the unit price is $0.38 per yard.
Answer:
The vertex is the point 
Step-by-step explanation:
we have

we know ow that
The equation of a vertical parabola into vertex form is equal to

where
(h,k) is the vertex of the parabola
Convert the equation into vertex form
Group terms that contain the same variable, and move the constant to the opposite side of the equation

Factor the leading coefficient

Complete the square. Remember to balance the equation by adding the same constants to each side


Rewrite as perfect squares

therefore
the vertex is the point 
Im pretty sure it would be product