Step-by-step explanation:
Since the focus lies on the x axis, and the diretcrtirx is a vertical line, we have a sideways parabola so we have the equation
where h,k is the vertex and
p is the distance from the vertex to the focus or the distance fromcthe vertex to the directrix.
Since the focus is 1.5, and the directrix is -1.5 the vertex is (0,0) so we have
We know p is 1.5 so we have
88.50-75=tip=13.5
13.5/75=0.18=18%
18% tip
Notebooks=x
pens=y
7=2x+y
8=x+5y ==> x=8-5y
substitute into the first equation
7=2(8-5y)+y
7=16-10y+y
7=16-9y
-9=-9y
y=1
now substitute y to find x
x=8-5y
x=8-5(1)
x=8-5
x=3
assuming you want amount of money for each item, a notebook is $3, and a pen is $1.
They are the same distance from 0