June 2010 Integrated Algebra Regents Exam 15 – 21

15. (2) 2
Lines are parallel when their slopes are equal (or when both are vertical). y = 2x – 7, slope is 2. if we transform y – kx = 7 y = kx + 7 it becomes clear that k must also be 2.

16. (4) one-half the difference of n and 3
Hmm. It’s half the parentheses. Half of what? Half of… the difference.

17. (3) 40. But this one is a guess.
I think they mean the median (second quartile….  $latex  \frac{2}{4}$ ?) Halfile?  LOL, I like that. So if we pretend that these are twelve students in a class, the halfile, I’m sorry, I mean “median”, that would be the average of the two middle numbers, 35 and 45. But how in the world does this question make any sense at all? Why would anyone want to know this? Absolutely beyond me. And I’m still not sure I’ve interpreted this mess correctly.

18. (4)
I like to spread this sort of thing out:   and just start canceling. (Yes, there are short cut rules, and if you know them well, and never make mistakes with them, use them. But no harm in spreading stuff out, until and unless the exponents start getting huge)

19. (3) 3
Plug in, that’s fastest. Or find the big common denominator, 6, and rewrite as and drop the denominators (ok to do, since they cannot be zeros) and solve 2x + 3(x+1) = 6x. You get the same place one step faster by multiplying each term by 6.

20. (1) 9
I would suggest symbolizing this, then plugging in:  . For some people the phrase “subtracted from” is tricky. Sorry, I can’t help with that. You could also write the same equation and solve: or , and the question asks for the positive answer.

21. (1) [5, 12)
The square brackets mean “or equal to” and the parentheses do not.