4 because you would say "forty three thousand..." three would be the one thousands place, and 4 would be the ten thousands place.
Answer:
C.
Step-by-step explanation:
The coefficients of the expansion of (a + b)^2 are 1 2 1, which is the third row of Pascal's triangle.
For (a + b)^3 they are 1 3 3 1 which is in the 4th row, and so on
So those for the (a + b)^n are in the (n + 1)th row.
Answer: 
Work Shown:

This can be rewritten into 
We have equation:
t=20x+31
x is number of years after 1997.
To calculate number of laptops in 2005:
x=2005-1997
x=8
t=20*8+31
t=160+31
t=191
In year 2005 school had 191 laptops.
The answer would be D.
you would start by choosing one of the variables to eliminate, i chose to eliminate X first. in order to eliminate X, i had to multiply the second equation by -2. X then cancelled out, and i solved for the Y the same way you would a 1 step equation. Y=-4
I then took the first original equations, plugged Y in, and solved for X. X=3.
Hope this helps!