All posts by mathconfidence

Get the Math and Points! Domain and Range (Which comes 1st in the alphabet?)

CC Alg I Jan 2018 12
Domain means x values and Range means y. 
D comes before R in the alphabet and x is before y.
This problem gives us x values so use them to find y.
f(x) = 2x^2 – 8
f(-2) = 2(-2)^2 – 8 = 2(4) – 8 = 0  (This narrows it down to answers (3) or (4)!)
f(3) = 2(3)^2 – 8 = 2(9) – 8 = 10 (This makes the answer jump out at ya!)
f(5) = 2(5)^2 – 8 = 2(25) – 8 = 42
Can also use the table from the TI-84 🙂
CC Alg I Jan 18 12

Get the Math & the Points! Jan 2018 CC Alg I Regents #6


Look for the point that does not make the equation true.
This is a very accessible question as all the x values in the choices are negative integers (-4, -3, -2, and -1) and will easily be found on the table.
When x = -4, y = -60 check
When x = -3, y = -24 check
When x = -2, y = -6 check
Um, when x = -1…
Most, if not all students, can build understanding of Math and critically think while gaining points to pass the Regents!  This question from January 2018 asks the student to notice the word not and to find the point that does not belong.

2 points 🙂

March 2018 Brain Puzzler Solution

Q: Leaving at 8:00 AM, if Ms. Brown drives at an average speed of 40 miles per hour, she will be late by 3 minutes. If she drives at an average speed of 60 miles per hour, she will be early by 3 minutes.  How many miles per hour does Ms. Brown need to drive to get to work exactly on time?

A: 48 miles per hour

There is a 6 minute difference between the fast (60 mph) speed and the slow (40 mph) speed.  This 6 minutes is 1/10 of an hour.
Distance = rate x time.  The two distances are equal so:
We can figure out how long it would take at 60 mph and go from there.
40 (t + .1) = 60 t
40t  + 4 = 60 t
4 = 20 t
4/20 = t = 1/5 hour
So it will take 1/5 hour at 60 mph which is 12 miles. (1/5 hour = 12 minutes)
It will take abit longer at 40 mph:
1/5 hour + 1/10 hour =
.2 hour + .1 hour = .3 hour at 40 mph  which is also 12 miles. (.3 hour is 18 minutes).
If Ms. Brown was exactly on time it would take her 15 minutes to go the 12 miles.
12 miles in 15 min = 48 mph.