Excel column A same value and column B value combine in Column D

Please help looking for the excel formula:
The column A have the same value, column B is qty, combine in text with '+' in column D, the column C is a,b,c, sample picture below, the Column D is in text.

This is quite an easy feat using a simple DAX measure.

There should be a build-in add-on called Power Pivot for you in ms Excel 2016. If you haven't already enabled it then have a look here. Power Pivot allows us to:

• Select your data (including headers);
• Click 'Add to Data Model' on the 'Power Pivot' tab. A pop-up should appear, you can close this for now;
• Under the same 'Power Pivot' tab, now click 'Measures'>'New Measure';
• Select the right table and give the measure a name that makes sense, for example 'TEXTJOIN';
• In the formula box apply the following formula: =CONCATENATEX(Table1,[Qty],"+"). Apply the appropriate tablename before clicking 'OK';
• In the same tab, now click 'Manage' and under the 'Home' tab in the pop-up window click 'PivotTable';
• Choose where to output the new table, drag 'Items' to rows and the measure you just created to values.

The output then, should look like:

Note: I removed 'Grand Totals'.