Your answer would be 19.25
I think the answer is :
In Geometry, we have several undefined terms<span>: point, line and plane. From these three </span>undefined terms<span>, all other </span>terms<span> in Geometry can be </span>defined. ... The first term<span> is point. The second </span>term<span> is plane. And the third </span>undefined term<span> is the line.
</span>
Hope This Helps.
An= A1 + d(n-1)
An= 170 + (-85)(n-1)
An=170-85(n-1)
An= 170-85n+85
Answer: An=255-85n
