Anybody good at algebra?

[The Howling Wolves]

Remember: sqr(b)*sqr(b) = b

Ya Sledge.....but wanted him to get that far and ask the ?

I am amazed that I can still recall this being I graduated from HS in 1962!
College in 71 with serving our country in between.

 

[profdlp]

...Question 'b' is harder how do I just get the 'b' from the sqr(b)? Hmm

Picture it using actual numbers.

If you had sqr(9) on one side, what then?
Square both sides. Your sqr(9) magically becomes just "9", because:

sqr(9) X sqr(9) = 9

Remember what BugMeister said:

...what you do to one side of the equation, you must also do to the other...

Whatever is on the other side is also squared and becomes {itself} X {itself}


EDIT:

Remember: sqr(b)*sqr(b) = b

Clicked the wrong thing while replying and had to start over. It took you a lot less words to say what I was trying to tell him.

 

[Benjamin Hall]

Umm..... I'm not a mathemetician, sorry :/

 

[BugMeister]

- on reflection, neither am I

heh, heh..!!

 

[SledgeDG]

@THW:I didn't want to give him the result...rather have him recall basic rules. sorry if in doing so I spoiled your plan.
I'm actually enjoying this...haven't had the need to recall those calculations for pretty much an eternity now either

@Prof: my explanation is shorter... true but some ppl might understand better if they go the long way around

Perhaps I should register with Big Y (they run a homework helpline over here)

-DG

 

[Benjamin Hall]

- on reflection, neither am I

heh, heh..!!

Very nice, lol. I could maybe do it, but I despise doing math. :/

 

[profdlp]

Umm..... I'm not a mathemetician, sorry :/

Math is just a set of rules. Play the game right and use the rules in their proper order and you'll win every time.

(Easier said than done, I know.)

It's no fun, but LOTS of practice is the best idea. You wouldn't shoot one free throw, sink it, then decide you had it down pat. But doing it over and over and over and...

 

[Benjamin Hall]

Don't confuse me with your foreign language talk D=

Ehhhh

 

[profdlp]

What? Don't they play basketball in Wisconsin?

 

[madtownidiot]

No, what he's saying is in Wisconsin, people don't need to practice at anything. We always get it done right the first time.

 

[arkhi]

I miss math so much I feel like doing your homework LOL. Let me think about it. Hmmm..

EDIT: So I wanted to use MS Math so I can template equations so it's easier to understand and that solve it a bit, but that thing freaking did it for me. So here it is. I'm going to leave the last 2 steps out since I don't want to spoon feed. The last number is up to you okay?

 

[Boomstick777]

Is this the correct answer for question 'b'

b = k/a + 2

I used this method
a = sqr(b)/k + 2
a x sqr(b) = sqr(b)/k + 2 xsqr(b)
a x b = k + 2
a x b/a = k/a +2


Answer - b = k/a +2

 

[Kirsch]

When did they add letters

 

[Francis93]

Nah. I suck at Algebra.

 

[Dwarf]

Let's go through this step by step.

a = sqr (b) / k + 2

sqr (b) / k = a - 2

sqr (b) = k (a -2)

sqr (b) = ka - 2k

b = (ka - 2k) x (ka - 2k)

b = k²a² - 4k²a + 4k² (answer)

Check using a = 6 and k = 3

b = (3² x 6²) - (4 x 3² x 6) + (4 x 3²)

b = 324 - 216 + 36

b = 144

Substituting b = 144 into the first equation, a = sqr (b) / k + 2, we get

a = (sqr (144) / 3) + 2

a = (12 / 3) + 2

a = 4 + 2

a = 6

So the answer is

b = k²a² - 4k²a + 4k²

Not bad, considering that it is about 30yrs since I did any Algebra. Hopefully, this should help you with the rest of the questions if you approach them in a similar way. Don't forget to do the checking, substituting actual numbers, as shown above. You will need to work out for yourself suitable numbers to use at this step.

 

[Kirsch]

Nice Job Dwarf!!

 

[mickey megabyte]

anybody good at washing up?

i've got a nice pile of dirty dishes growing in my kitchen..

 

[Dwarf]

Nice Job Dwarf!!

Thanks.

anybody good at washing up?

i've got a nice pile of dirty dishes growing in my kitchen..

I think I'll give that one a miss. :sarc:

 

[The Howling Wolves]

Let's go through this step by step.

a = sqr (b) / k + 2

sqr (b) / k = a - 2

sqr (b) = k (a -2)

sqr (b) = ka - 2k

b = (ka - 2k) x (ka - 2k)

b = k²a² - 4k²a + 4k² (answer)

Check using a = 6 and k = 3

b = (3² x 6²) - (4 x 3² x 6) + (4 x 3²)

b = 324 - 216 + 36

b = 144

Substituting b = 144 into the first equation, a = sqr (b) / k + 2, we get

a = (sqr (144) / 3) + 2

a = (12 / 3) + 2

a = 4 + 2

a = 6

So the answer is

b = k²a² - 4k²a + 4k²

Not bad, considering that it is about 30yrs since I did any Algebra. Hopefully, this should help you with the rest of the questions if you approach them in a similar way. Don't forget to do the checking, substituting actual numbers, as shown above. You will need to work out for yourself suitable numbers to use at this step.

Dwarf,
Nice job going step by step in solving his problem.
Could have done that early on in the post but thought it was important for the OP to practice and learn on his own. Isn't that the way we learned how to algebra?

 

[Dwarf]

I'm leaving the rest for him to work out on his own. Besides, the image isn't very clear with the other equations.