starstruck567
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Hi Looking for A helping hand


The first term in an arithmetic sequences is -9. The fifth term in the sequences is 15. The tenth term in the sequences is 45. Write the explicit form that would be used to find the nth term in the sequence. Show the steps you took to write the simplified explicit form.

Respuesta :

s1m1

Answer:

an = a1 + 6(n-1)

Step-by-step explanation:

a1 = -9, a5= 15, a10 = 45

Since is an arithmetic sequence we only add or subtract something to get to the next term. Since we got from -9 to 15 we know that we must add something and that we add it 4 times the same amount to get from -9 to 15.

a1= -9

a2= -9+6 = -3

a3= -3+6 = 3

a4= 3+6 = 9

a5= 9+6 = 15

We add 6 each time.

The explicit formula is an = a1 + 6(n-1) because

for example a5 = a1 the first term + 6* (5-1) times

                    a5 = -9 + 6* 4 = -9 + 24 = 15✅

                    a10 = a1 + 6* (10-1)

                    a10 = -9 + 6*9 = 45✅