Step-by-step explanation:
the third of 7 consecutive numbers is 12.
so, this looks like
..., ..., 12, ..., ..., ..., ...
that means the numbers have to be
10, 11, 12, 13, 14, 15, 16
the sum is then
16+10 + 15+11 + 14+12 + 13 = 3×26 + 13 = 91
Answer:
143
180 - 37 = 143.
We know this because y + 37 = 180
so we can does 180-37 to get our answer.
y = 2x
1. attendee = x
2. cost = y
3. for each attendee [x], you have $2 of cost, so for each 1 x, you have 2 as result
4. Thus, y = 2x
In arithmetic sequence: a₂ - a₁ = a₃ - a₂ {common difference}