Answer:
The 39th triangle number is 780
Answer:
91+c
Step-by-step explanation:
The equation to find the perimeter of the triagle is every side added together. We know 2 sides which means we add them to get 91. Then we know we don't know the next number but we add it so we just put the c where the next number to be added would go.
The integer that represents this -45.
A
this is an arithmetic sequence whose n th term ( explicit formula) is
= 
+ (n - 1 )d
where d is the common difference and the first term
here d = 10 - 8 = 8 - 6 = 6 - 4 = 2 and = 4, hence
= 4 + 2(n - 1 ) = 4 + 2n - 2 = 2n + 2 → A
Set up an equation to see how this makes sense.
Let X be your original number.
So...
2(3x-7)-22/6=-3
6x-14-22/6=-3
6x-36/6=-3
6x-36=-18
6x=18
X=3
