Round 56,477,812 to the nearest hundred thousand,

56,500,000.

Step-by-step explanation:

56,477,812 rounded to the nearest hundred thousand:

The 4 is in the hundred thousands place, so we'll look at the next digit to the right of that, which is the 7:

56,477,812

Since 7 is more than 5, we'll have to go up a number, which will be the 4. Afterwards, we'll have to replace all the digits after the 4 with zeros.

56,500,000.

-329

Step-by-step explanation:

1st term a1 = 3, common difference d = -4

84th term,

3+(84-1)(-4)

= -329