In the number 956,783,529, how does the value of the digit 5 in the ten millions place compare to the digit 5 in the hundreds place?

The value of 5 in the tens millions is greater than the 5 in the hundred place. I can say that very easily because every place value increases by times 10. If you were at 5 in the hundreds and go to 5 in the ten millions you would go from place value to place value by times 10 which in total will give you 100,000 times. That's a lot.

1.17+3.99a. you combine the terms with a to create 3.99 and the 1.17 stays because it has no like terms or a variable