Hello, Marymack!
We know that in a geometric sequence defined by

and

, the sum can be calculated the following way:
Answer: x goes from 0 to 2, y changes from 0 to -2
Step-by-step explanation:
Rounding numbers means you change the number to a closer, easier number. For example if you want to round 56 to the nearest tenth, it would round to 60.
Estimating numbers is when you guess numbers. For example, if you want to estimate the measure used to measure a bed, i would estimate feet.
I hope this helped:))