17.10 is the sale price.
I don’t know how to explain but hope this helps.
If $4.59 = 5.4 peanuts
$x = 7. 8 peanuts
Cross multiply and you get:
5.4x = (4.59)(7.8)
x = ((4.59)(7.8)) / 5.4
x = $6.63
It should look like a parabola with the part below x-axis cut off. the left side starts from x=-1, opening upward & to the left, the right side starts from x=2, opening upward and to the right.
So to complete the square in
ax^2+bx+c=d form
make sure a=1
subtract c from both sides
take 1/2 of b and square it
add that to both sides
factor perfect square
1x^2-1x-2=0
a=1
move c to other side
add 2 to oth sides
x^2-1x=2
take 1/2 of b and square it
1/2 of -1=-1/2
squaer it
1/4
add that to both sides
x^2-1x+1/4=2+1/4
factor left side
(x-1/2)=2+1/4
first blank is 1/2
2+1/4=8/4+1/4=9/4
blanks are
1/2 and 9/4
