We need to add 10 to each of these terms to make the sequence 8, 6, 4, 2, 0…įor instance, -2 + 10 = 8, -4 + 10 = 6 and so on. The -2n sequence is simply the negative 2 times table. We need to add 10 to each of these terms to make the original sequence, so the nth term is -2n + 10. For example, in the sequence 8, 6, 4, 2, 0… the terms decrease by 2 so we start by writing -2n. If a sequence is decreasing from one term to the next, the number in front of n in the nth term will have a negative sign. Write this after the answer to step 2: ‘4n – 1’.Īnd so the nth term of our sequence is 4n – 1. Subtract the difference from the 1st term: 3 – 4 = -1. Write this difference with an ‘n’ after it: ‘4n’. Find the common difference: The terms increase by 4 each time. Add this to the answer written in step 2.įor example, we will find the nth term for the sequence starting 3, 7, 11, 15, 19….Subtract the difference from the first term in the sequence.Write this difference with an ‘n’ after it.
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