Find the value of the letter and number below
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a4 = 123

Step-by-step explanation:

Here, we want to find the value of the 4th term

we simply have n as 4

substituting this, we have;

a4 = (a3)^2 + 2

But a^3 = (a2)^2 + 2 and

so we have ;

a4 = [(a2)^2 + 2]^2 + 2

But a2 = (a1)^2 + 2

a4 = {[(a1)^2 + 2)]^2 + 2}^2 + 2

Now, substitute the value of a1

a4 = (1)^2 + 2)^2 + 2)^2 + 2

a4 = (1 + 2)^2 + 2)^2 + 2

a4 = (3^2 + 2)^2 + 2

a4 = 11^2 + 2

a4 = 121 + 2

a4 = 123

just sum

10 + 10 = 20