Answer:
If you look over the steps you can see that until 4x + x + 3 = 18, evertything is dandy. But the step after that 4x + x =21 seems a bit fishy.
Think about it they subtract 3 from both sides so the first side is correct
4x + x, but they added 3 to the other side:

not
4x+x = 21
Then we solve for 4x + x = 15

To solve for y we use :
y = x+3
y = 3+3 = 6
so (3,6) is the right answer
The answers are #1 45 #2 24 #3 10
Answer:
c
Step-by-step explanation:
150 is a good sample of a middle school and students at lunch is random again because most students eat lunch
We know that
At sea level, the height is 0 and
the pressure is 98 kilopascals
At 1000 ft, the height is 1000 and
the pressure <span>decreases about 11.41%
</span>i(100%-11.41%)/100----> (0.8859)
therefore
1) at 1000 ft--------> the pressure is 98*(0.8859)----------> 86.82 kilopascals
2) at 2000 ft--------> the pressure is 86.82*(0.8859)-------> 76.91 kilopascals
3) at 3000 ft--------> the pressure is 76.91*(0.8859)-------> 68.14 kilopascals
4) at 4000 ft---------> the pressure is 68.14*(0.8859)-------> 60.36 kilopascals
the answer is
<span>The pressure at an altitude of 4000 m is about </span>60.36 kilopascals