Let one pen be [tex]x[/tex] and one pencil as [tex]y[/tex], we can produce two equations in terms of [tex]x[/tex] and [tex]y[/tex]
[tex]7x+2y=6.59[/tex] ------> Equation 1
[tex]7x+5y=7.55[/tex] ------> Equation 2
We can use either Elimination or Substitution method. Let's try the substitution method
Rearranging equation one to get [tex]7x=6.59-2y[/tex] and substitute into equation 2, gives
[tex](6.59-2y)+5y=7.55[/tex]
[tex]6.59+3y=7.55[/tex]
[tex]3y=7.55-6.59[/tex]
[tex]3y=0.96[/tex]
[tex]y=0.32[/tex]
We can use either equation one or equation to work out [tex]x[/tex]
[tex]7x+2(0.32)=6.59[/tex]
[tex]7x=6.59-0.64[/tex]
[tex]x=0.85[/tex]
The price of one pen is $0.85
The price of one pencil is $0.32
