Melody

Bill Billerson:

How much wood could a woodchuck chuck, if a woodchuck could chuck wood?

I like Serena:

\displaystyle \frac or \dfrac work to make fractions bigger.

Furthermore, many sites support multiple delimiters for latex that behave slightly differently.
If you use $$\frac 1 2$$ or [ math ]\frac 1 2[ /math ] you often get bigger ("displaystyle") latex, while $\frac 1 2$ generates small ("inline") latex.

Stu:

Yes, you raised two key points. One was that two halves of a fraction at negative make a positive overall fraction. This was a question I was wondering about but didn't state.
Second was that this is easy, but I was trying to fit to the equation x=c-b/a, and trying to get it to look like ax+-b=+-c. when doing so, I guess a and b, could be either number value or x term values, and it wouldn't matter. That is 2t+5t=15 would fit in the equation the same as 7+8=7t, a,b,c respectively to both terms.

Thanks again for a good explanation.

zethwolf:

ln(x+3)=ln4+ln(x-3)

I've been having trouble with this problem. I keep on getting x+2=x

Stu:

Regarding the maths
x = (c-b)/a where ax+b = c (what is the name for this formula?) ..
You should not remember this as an equation. You have simply rearranged ax+b=c and you need to know how to do it not just memorize the answer. Grammar Fascist has given you some really good pointers for this.
and
Quadratic formula where ax²+-bx+-c=0 => x = (-b+-Sqrt( b2 -4ac))/2a Those brackets need to be added.
This might help you remember the quadratic formula. Remember, the equation must be of the form ax²+bx+c = 0

http://www.youtube.com/watch?v=O8ezDEk3qCg

Give me as much help as you can. Specially identifying what is able to be made into an equation for a quadratic formula and what is to be left as a std x= c-b/a.
So for the following questions.. the difficulty I have is with the sign values of a/b/c and transposition of terms. I get how to transpose. but when working backwards/ slotting the answer I get in as x, it is often not correct. So I'd like a little help with steps.

1)
3x-8=1
x= 1- (-8) / 3
x= 1+8 /3
x= 9/3
x= 3
3*3-8=1 (correct.)
1)
3x-8=1
You want the lots of x by themselves so you need to add the 8, but if you do it to one side you must do it to the other side as well. The equation must always 'balance'
3x-8+8=1+8
3x=9
Now you need to get rid of the 3 so divide both sides by 3
3x/3=9/3
x=3
This is how it should be done.
2)
7t-5= 4t+7
7t-5-4t= +7
7t-4t-5= +7
3t-5= +7
Forget your next 3 steps do it the same as the last one
x= (7- (-5))/3
x=12/3
x= 4
7*4-5= 4*4+7
28-5= 16+7
23= 23 (correct)

3x+4= 4x+3
3x-4x+4=3
-1x+4=3
Good so far now do it the same as the one i showed you
x= (3- (+4)/-1
x= (3-4)/-1
x= -1/-1 = -1?
(3*-1)+4= (4*-1)+3
-3+4= -4+3
1= -1 (incorrect)

-3x+4?=4x+3
-3x-4x+4= +3
(-7x)+4 ≠ to +3 --> to move the +4 from the front of equation to the back of the equation do I need to alter its symbol?
Now i am lost
Start from here
3x+7= 7x+2
3x-7x+7= +2
-4x+7= +2
Forget the next 3 lines do it the other way
x= 2-(+7)/-4
x= 2-7/-4
x= -5/-4
(3/1*5/4)+7/1= (7/1*5/4)+2/1
(3*5/4*1)+7/1=(7*5/4*1)+2/1
15+28/4= 35+8/4
43/4= 43/4 (correct)
Please show simpler way to the above~ thanks.

(x+7)= 7*(x+2)
(x+7)= 7x+14 --> can't work out steps to make equation. >>
x+7 = 7x + 14 The brackets had no added meaning
Now work it the same as you did for the others

Try cleaning up everything you have done and represent a tidied up version. Thanks Stu.
(x+7)= (7x+14)
(x+7) (-7x+14) =0
(x+7) -7(x-2) =0 --> yep just can't get it.
-2(x-3)=-12
-2x+6= -12
x= -12-6/2
x=-18/2
x=9
-2*9-3= -12 (not correct.)


or<-2x+6+12=0 >
2x+18=0 ( I can't see how it works, even if 2*-9 or 2*+8 we can not +18 to get 0 unless x is = to 0 its self but which in my calculation I couldn't solve to be 0.

3(2t+1)= 4(t+2)


5m-3= 5(m-3) +2m


17(x-2)+3(x-1)=x+24 (please do entire maths expanded through all steps.)

Katlina:

If the diameter of a wheel is 5 ft, about how many miles does the wheel
travel if it makes 134 revolutions? Use 2
7
2
for π. (Hint:1 mi 5280 ft.) It Also says round to the nearest tenth. II got .4 of a mile am I right?

GrammarFascist:

Woops! You had the units right...it asked for miles. My bad--good on ya for stickin' the landing on those units! http://web2.0calc.com/questions/posting.php?mode=reply&f=2&t=8763#

kaylinfrost:

What are the solutions of the equation x^2-3x-4=0

rachel123:

Use the Laws of logarithms to rewrite the expression in a form with no logarithm of a product, quotient or power.

Problem: log(sqrt x^2+6/(x^2+12)(x^3-2)^15