Math problem Pissing me off!!
 

My 12 year old just came to me for help on this math problem.


What two numbers have a product of 24 and a difference of 5?

I pride myself in being able to solve his math problems with ease. Especially a 6th grade math problem.

I do not know if I am just not awake enough but I cannot come up with the answer.

Someone want to explain this one to me?

I just woke up!! 8*3

Never mind!!

I guess typing it out helped. I was reading product and thinking sum in my head.

There's nothing like a 12 year old to teach you how much you have forgotten about math.

X*Y=24
X-Y=5

X=Y+5
(Y+5)*Y=24
Y^2+5*Y-24=0

D=5*5+4*24=121
Y=(-5+-sqrt(121))/2 = 6/2=3
X=3+5=8

Second degree equation baby ! That`s how you do it mathematically.

Aurel

1*24=23
2*12=10
3*8=5
4*6=2

I remember taking some college night classes and at one point we were doing quadratic equations. A lot of the students were using tutors because the class was very progressive and spent little time on any one topic. While doing homework one night, my wife called me to the TV and there was a class doing the same exact equations on a PBS station. It was an 8th grade class. :)

The instructor was involved in the jettisoning of human waste at NASA way back when.

Interesting problem. Makes me miss my Algebra days.

Well, if we're going to do math let's do it right - there are two correct solutions - note the +- in Aurel's equation...

that's right.
x=-3
y=-8
is also correct...

Bush hates math.

(I bet he really does!)

When visiting family, I ended up helping my 17 yr old sister-in-law with her homework. Now note that I am an engineering student, and have been through Calc 3 and Differential Equations. It took me the longest time to figure out synthetic division so that I could help her, I felt like a total dumbass. What is the saying about being educated to the point of stupidity?

Here's one that made my son go nuts for 30 minutes.

"OK Max, what is 1+1 equal."

"Dad, thats so easy, its 2!"

"Nope, it's 3 or 1 but not two. Heres an example. Lets say I'm 1 and Mommy is 1. When you added us up we had you which made it another 1 or 3 total!"

"Dad, thats...hay, how'd you do that?"

I did straighten him out but only after having him think it through.

That's cute.... unless Max is 28. :p

Its more like 50% after the umteenth time. My kids passed in the 9th grade, thats the HIGH SCHOOL exit exam. So you only have to have an 8th grade education to graduate HS in CA and the lazy sobs called teachers can only get 50 percent of the 50 percent that don't drop out (gee that sounds like 25% to me) to pass. Gotta love those teachers unions. OOPS I forgot the passing grade is only like 50%, so maybe 12.5% really have an eight grade education after 12 years.

I suspect that most kids could do better if they wern't required to attend school at all. The finest LIBERAL education in the world.

MY kids arn't all that smart either. Its just that they had about 2 to 3 years education in a non CA public schools, and that was dance class, you know 5, 6, 7,8 likely the only real education they received in 1-12.

LA schools are not as bad as they say they are, they are worse, much much worse.

The same thing happens to me, I hate it.

I'm going into learning integration involving trig functions now...I can't remember for the life of me the basic properties of sin, cos, and tan, or some of their identities. Uggh...:mad:

Aurel, I liked the quadratic technique. It's one formula I haven't forgotten, I've had enough practice with it.

In college we had to take 2 advanced Math courses beyond Differential Equations. The problem: they were taught by the Math department, which means they were taught by math geeks.

They expected that you remembered every stupid math trick taught since kindergarden. The Quadratic equation is burned into ROM, but a bunch of the math tricks taught in geometry? no.

Any old geometry ticks don't work that well in non-euclidean space where parallel lines are not always the same distance apart.:)

Pick up one of those laminated trigonometry cheat sheets, it will have most of the basic equations, unit circle, etc. I picked one up at Barnes & Noble, it saved my ass in Calc 2. I was going back to school after a long hiatus, my trig class was literally 10 years before my Calc 2, and they expected us to remember everything. Uh, no.

i would/should be fired without my HP48GX. i own two of them.

LOL!!

I keep mumbling to myself as I help my son that computers do his now. Its good to know the mechanics of the problem but, in all honesty, if I caught any of my employees skiping the computer to do it the old fashioned way they would be in trouble.

I know it is important for him to understand this so I persevere.

Actually, I think you would want someone to think that way, lest he forget to change from rad to degree when he is doing an arc sine problem.