Question 1205896
M, Lee's amount of money with went shopping
p, price of shirt


Bought the 15 shirts
{{{M+150=15p}}}


Bought just 5 shirts
{{{M-5p=250}}}


Find p, the price of 1 shirt.
{{{system(M+150=15p,M-5p=250)}}}


prepare substitution for M.
{{{15p-150=M}}}
-
{{{15p-150-5p=250}}}
{{{10p=400}}}
{{{highlight(p=40)}}}