Note, if we want to write sqaured, or any other power for that matter, we use "^"

so 5 squared is typed as 5^2

Now, we want to figure out a pattern that links the underlined numbers. so let's write them out in a table:

let n represent the number that is underlined in the sqaured number

let f(n) be the function the relates it to the evaluated number

....n..............................f(n)

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....1...................2 = 1*2 = 1*(1 + 1)

....2...................6 = 2*3 = 2*(2 + 1)

....3...................12 = 3*4 = 3*(3 + 1)

....4...................20 = 4*5 = 4*(4 + 1)

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....n...................?

what do you think the general formula is?