Question 997227
x, pencil price in dollars
y, pen cost in dollars
{{{y=x+0.25}}}
Then the counted items with cost, {{{4y+5x=3.70}}}


Simply substitute for y.
{{{4(x+0.25)+5x=3.7}}}
Simplify and solve.
{{{4x+1+5x=3.7}}}
{{{9x+1=3.7}}}
{{{9x=3.6}}}
{{{x=3.6/9=4*9/(9*10)}}}
{{{highlight(x=2/5)}}} in dollars, being 40 cents for one pencil.