Answer:
x = 7
Step-by-step explanation:
3x - 9 = 12
3x = 12 + 9
3x = 21
x = 21 ÷ 3
x = 7
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
Step-by-step explanation:
W=N•D
W=(200)(1.3)
W= 260
m = 4b+3 mikes age
m +b <138 mike +brother less than 138
4b+3+b<138
5b +3< 138
b< 135
b <27
The oldest the brother can be is 26