What is the 20th term in the linear sequence 15, 7, -1, -9, -17

Hello from MrBillDoesMath!

-137

Discussion:

It appears the 8 is subtracted from each term in the sequcnes as we proceed from left to right. The equation describing the nth terms is therefore:

a(n) = 15 - 8 * (n-1)

          a(1) = 15 - 8(0) = 15

          a(2) = 15 - 8*(2-1)   = 15 - 8 = 7

          a(3) = 15 - 8(3-1)  = 15 - 8(2) = 15 - 16  = -1

          etc

The 20th term is given by

a(20) = 15 - 8(20-1)

         = 15 - 8 * 19

         = 15 - 152

         = -137

Thank you,

MrB

c. 27 units.

step-by-step explanation:

we are told that in circle a, ∠bae ≅ ∠dae.

we can see from our given diagram that in and ;

, as these are radii of our given circle.

therefore, by sas congruence postulate.

hence, side be will be equal to side de as corresponding parts of congruent triangles are congruent. so we can set an equation to find the value of x as:

now let us substitute x=17 in the expression for the length of be.

therefore, length of be will be 27 units and option c is the correct choice.