Answer: -81/35
Step-by-step explanation:
Answer:
an = 1/2 (n) (n+1)
Step-by-step explanation:
1,3,6,10,.........
3-1=2
6-3=3
Each term is different so there is no common difference. It is not an arithmetic sequence
3/1=3
6/3 =2
Each term is different so there is no common ratio. It is not a geometric sequence
1 3 6 10
+2 +3 +4
a1 = 1
a2 = 3
a3 = 6 = 2*3
a4 = 10 = 2*5
2x + y = x - y - 3 = 6
Add 3 to everything
2x + y + 3 = x - y - 3 + 3 = 6 + 3
2x + y + 3 = x - y = 9
2x + y + 3 = 9
2x + y = 6 = x - y
Add y to everything
2x + 2y = 6 + y = x
Since x = 6 + y substitute every x with 6 + y
2(6 + y) + 2y = x
12 + 4y = x
This is as simplified as I can get and then just place 12 + 4y into every x in the original problem then solve
