Please help if can and show work

One astronomical unit (1 au) is about 1.496 alt tag missing. kilometers. if you wrote this number of kilometers in regular decimal notation (for example, 528 and 3,459 are written in regular decimal notation), how many zeros would your number have?

If t8 = 4 and t12 = −2, find the first three terms of the arithmetic sequence.

Typically a point in a three dimensional cartesian coordinate system is represented by which of the following answers in the picture !