ask sql for multiplication two coloms and then division with sum of some rows : i have tables

**scores**

id name score item_id

1   rikad  90  1

2   rikad  80  2

3  rikad 70 3

4  reza 80 1

5  reza 80 2

6  reza 100 3


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**items**

id weight

1  0.5

2  0.2

3  0.3


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i want the output with new column call last_score ( (score x weight ) / "0.5 + 0.2 + 0.3 (sum of all weight that have same name)" )

id name score item_id weight last_score

1   rikad  90  1 0.5  last_score

2   rikad  80  2 0.2 last_score

3  rikad 70 3 0.3 last_score

4  reza 80 1 0.5 last_score

5  reza 80 2 0.2 last_score

6  reza 100 3 0.3 last_score