Answer:
The cost of
of grass sod is $7
The cost of one piece of shrub is $9
Explanation:
Let
represent
of grass sod and
represents one piece of shrub
Joe spent $
on
of grass sod and
pieces of shrubs (shelves)

Lisa spent $
on
of grass sod and
pieces of shrubs (Chevy)

from



Now put the
into










The cost of one piece of shrub is $9
Now put the value of
into
to get value of






The cost of
of grass sod is $7