+0  
 
0
48
1
avatar

If the first term of an arithmetic sequence equals the third minus the second, and the fourth term is 18, what is the first term?

 Aug 16, 2021
 #1
avatar+12248 
+1

If the first term of an arithmetic sequence equals the third minus the second, and the fourth term is 18, what is the first term?

 

Hello Guest!

 

  a = c  - b

  d = 18

a - a - b - a - c - a - 18

 18 - 3a = a

  18 = 4a

   a = 4.5

 

 a,    b,    c,     d

4.5,  9,  13.5, 18

laugh  !

 Aug 16, 2021

42 Online Users

avatar