Look up a value in last sheet and cop it to the next

[mezza89]

Evening all hope someone can help!

Very rusty on excel these days.

Please see the attached spreadsheet:

When you see the sheet first sheet is irrelevant as new tax year but there after i would like:

P9 =
Look up value of P9 in previous sheet and add the value of L9 in active/current sheet.

Q9 =
Look up value of Q9 in previous sheet and add the value of M9 in active/current sheet.

Hope you can help and thanks in advance.