Find an explicit rule for the nth term of the sequence. The second and fifth terms of a geometric sequence are 20 and 1280, respectively.

Step-by-step explanation:

in a geometric sequence there is a constant factor x that is multiplied with every previous term to create the next one.

a2 = 20

a5 = 1280 = a2×x×x×x = a2×x³ = 20x³

64 = x³

x = 4

=> a1 = 5

therefore

an = an-1×4 =

n > 1

the sum of all the angles in a triangle are equal to 180

so you can add   the 3 given angles together to equal 180:

5y + 2y + 2y = 180

or since all three angles have the same letter, combine the 3 angles to equal 180:

9y = 180

in simplified version   it would be x ≤-4

step-by-step explanation:

multiply each term in x ≤-4 by -1