Well I don't get what the other parts of the question is asking, but they can make 240 packs of pencils.
18(y-5)^2=x+3
do the algebra to make it into =x form
x=18y^2-180y+447
then you take the form of the focus, you can do the math
(-215/72, 5)
The answer should be 2 13/30.
Remember you can do anything to an equation as long as you do it to both sides
8-(3+b)=b-9
remember the distributive property
a(b+c)=ab+ac
distribute that invisible -1
-(3+b)=-1(3+b)=-1(3)-1(b)=-3-b
8-3-b=b-9
add like terms
5-b=b-9
add b to both sides
5=2b-9
add 9 to both sides
14=2b
divide both sides by 2
7=b
b=7
