Please help me with this question

  20

Step-by-step explanation:

The average term in the series is the average of the first and last terms:

  average term = (25 +101)/2 = 126/2 = 63

The sum of the series is the product of the average term and the number of terms:

  Sn = n(average term)

  1260 = 63n

  1260/63 = n = 20

The number of terms in the series is 20.

y=−9/2x+10

step-by-step explanation:

let's solve for y.

0−9x−2y=−20

step 1: add 9x to both sides.

−9x−2y+9x=−20+9x

−2y=9x−20

step 2: divide both sides by -2.

−2y

−2

=

9x−20

−2

y=

−9

2

x+10

no

step-by-step explanation: