Add two sums, take on from the other, then multiply the result by 2. How

Sorry, I know this is really easy but I can't solve it and it's holding me up.

I've two sums, I need to add both, take one from the other, then double the result.

SUM(C2:C5) = 10.
Sum(C6:C7) = 7
so the result of the following is 3.

EXCEL =SUM(C2:C5)-SUM(C6:C7)

I now need to multiply the answer by 2 to get 6 but if I try

EXCEL =SUM(C2:C5)-SUM(C6:C7)*U2 I get -4

Where am I going wrong please?

Please try this and see

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