At point A, the reading on the altimeter is 450; at point B, it's negative 50. Was there a typo here? It's not clear what the question is.
Answer:
We need to subtract both equations. 2x3+30x-130-2x3+3x+520
that gives
30x-130+3x + 520
33x+390
D is answer
Answer:

Step-by-step explanation:

Check:

OK.
Answer:
1651
Step-by-step explanation:
let s say that the price before the increase is x
to apply an increase of 9% it does x + x*0.09 = x*(1+0.09)=x*1.09
and we know that this value is 1800
so
x*1.09=1800
<=>
x = 1800/1.09=1651.376147
to the nearest penny it gives 1651
Answer:
there was a 16% increase since 2010 to 2012
Step-by-step explanation:
lets say the train had 100 people on it in 2010 and in 2011 it had an 8% increase which then brings you to 8 plus 100 and you get 108.
Now in 2012 there was an increase 8%, so you will add 8 to your previous answer 108 and receive 116. So now there was 16 more passengers in 2012 than in 2010. Transfer the 16 passengers into 16% and you now have your answer.