Question

I need help with this, and a step by step explaination would be very helpful! Thank you!

Answer 1

18

Explanation:

The summation symbol is telling you there are 4 terms of the sum. The values of x in the terms range from 1 to 4.

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The expanded form of the sum is ...

(1 +2) +(2 +2) +(3 +2) +(4 +2)

= 3 +4 +5 +6 = 18

The sum is 18.

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Additional comment

The sum can be rewritten as ...

`\displaystyle \sum_(x=1)^4{(x+2)}=\sum_(x=1)^4{x}+\sum_(x=1)^4{2}=(4(4+1))/(2)+4*2=10+8=\boxed{18}`

This way, you need to know the sum of integers from 1 to n is (n/2)(n+1). It may be easier just to write the terms out as we have done above.