Puzzle 95: What's it worth?

Each symbol has a numerical value. The total for the symbols is written at the end of each row and column.  Can you find the missing total that should go where the question mark has been put?  Explain your strategy.

​​Extension:

Apply your strategy in the similar puzzle below.  What is the value of each piece of fruit?  Also, what are the missing totals (the question marks)?  Explain your strategy.

Source: nrich.maths.org