Excel Formula Calculation IF AND ETC -

i can't use picture, because of reputation. try explain problem. please me formula.

i have table 1. have enter alphabet on column 1 , column 2 on table. ex. entered on column 1 , x on column 2. have table 2. table 2 have column 3 column 4 , column 5. column 3 , column 4 alphabet table 1's columns. column 5 number. when enter these alphabets (a , x) on table 1's columns, formula scan table 2's column 3 , column 4 each lines. if column 1 = column 3 , column 2 = column 4, formula plus column 5 each line , write table 3's single column.

** formula can't plus negative numbers.

for example.

table 1 column 1 : column 2 : x

table 2 line 1 - column 3 : a column 4 : c column 5 : 50

line 2 - column 3 : a column 4 : x column 5 : 60

line 3 - column 3 : a column 4 : x column 5 : -20

line 4 - column 3 : a column 4 : x column 5 : 40

table 3 total : 100

i dont understand formula makes... sintax of if:

if(boolean statement, instruction if true , instruction if false).

you can read more information if: https://office.microsoft.com/en-us/excel-help/if-hp005209118.aspx

the column 3, 4 , 5 depends on content of column 1 , 2... can build logical function if formula in columns 3, 4 , 5.

the result in table 3 sums positive numbers of lines have 'x' on column 4... can use sumifs function achieve this... sumifs function sums range of cells if meet logical criterias. here, made function throws total value of table 4:

sumifs(e1:e4;d1:d4;"=x";e1:e4;">0")

read more informationo sumifs: http://office.microsoft.com/en-us/excel-help/sumifs-function-ha102753226.aspx?ctt=1

also, suggest use wizard build sumifs formula... it's pretty friendly.