All Answers

+118725

Guest:
what are the length and the width of the rectangle with an area of 96cm2

There a lots of answers. The rule is that l * w = 96

MelodyMar 20, 2014

+118725

princeshakim:
Tahlia arranged her classroom desks in various equal rows and columns she had 120 desks which way could she not arrange her desks

Was this a multiple choice question?

If they make a nice rectangle then the number of rows X the number of columns must = 120.

MelodyMar 20, 2014

+118725

jrjytrhfnggf:
(4t) (1/2t by the power of 1/2)

i know that you have tried but the meaning is still not very clear

this is what you have asked

4t * (1/2) * t ^1/2 = 2t*sqrt(t)

but maybe you meant

4t * (1/2*t) ^1/2 = 4t * sqrt(t/2)

or maybe you meant something else

Anyway, I hope that helps.

MelodyMar 20, 2014

+6252

Quote:
Pop's Cycle shop sells bicycles and tricycles. The number of bicycles is 1 less that 4 times the number of tricycles. All the bicycles and tricycles together have a total of 174 wheels. How many bicycles are there

not sure what exponents have to do with this

b = 4t - 1

2b + 3t = 174

substitute eq 1 into eq 2

2(4t-1) + 3t = 174

8t - 2 + 3t = 174

11t = 176

t = 16
so
b = 4(16)-1 = 63

RomMar 20, 2014

+118725

Lollie:
What 2 numbers multiply to be -49 and add to be 6?
I'd like an answer asap, if that's okay!

You have2 equations here to be solved simultaneously.

x * y = -49
x + y = 6 ==> y=6-x substitute this into the first equation to see if you can find a solution for y

It will be a quadratic equation.

Happy calculations.

MelodyMar 20, 2014

+6252

xy = -49
x+y = 6

y = 6-x

x(6-x) = -49

-x ²+6x = -49

x ²-6x = 49

(x-3) ² - 9 = 49

(x-3) ² = 58

x-3 = +/- sqrt(58)

x = 3-sqrt(58) OR x = 3+sqrt(58) and the corresponding y's are y=3+sqrt(58) OR y=3-sqrt(58)

clearly x+y=6

xy = 9 - 58 = -49

RomMar 20, 2014

+118725

CPhill:
So...we have only two complex roots!!

Note.........Any complex roots of a polynomial always occur in pairs!!

Hope this helps

Hi Chris,
You can see the answer without needing a second post just by using the preview function.

MelodyMar 20, 2014

+130561

So...we have only two complex roots!!

Note.........Any complex roots of a polynomial always occur in pairs!!

Hope this helps

CPhillMar 20, 2014

+118725

Guest:
What are the roots for P(x) = x^3 + 2x^2 -4

Quote:
At least one root is between 1 and 2

According to Descartes rule of signs, we have one positive root, and either two negative roots or no negative roots

Okay Chris,
I am not familiar with Descartes rule - Yes I know I could look it up - okay I did.

Now P(1) is negative and P(2) is positive therefore there must be at least root between 1 and 2. That is obvious.

http://en.wikipedia.org/wiki/Descartes'_rule_of_signs
EXTRACT
"Positive roots[edit]
The rule states that if the terms of a single-variable polynomial with real coefficients are ordered by descending variable exponent, then the number of positive roots of the polynomial is either equal to the number of sign differences between consecutive nonzero coefficients, or is less than it by an even number. Multiple roots of the same value are counted separately.

Are 2x^2 -4 counted as consecutive since there is a zero term inbetween ? If they are then there is 1 sign change. Hence there is 1 positive root.

Could you comment please Chris?
Thankyou.

PS i still think it was a copy error.

MelodyMar 20, 2014

+130561

2x^2-4x+3=0

First, let's see if we can factor this....nope!!

We could either use the quadratic formula or use the solver on this site

I'll use the latter

2x^2-4x+3=0

CPhillMar 20, 2014

+130561

Area of counter - area of "hole" =

(12*3) - (3*2) =

36 - 6 =

30 sq. ft.

CPhillMar 20, 2014

+130561

asin(6/11)

CPhillMar 20, 2014

+130561

Wow!! Those were pretty complicated!!

As suspected, only the third root is real (I'll let you calculate (THAT one!!) and the other two are complex.

Note.....if we have any complex roots in any polynomial, they ALWAYS occur in pairs. We can't have an odd number of complex roots.

CPhillMar 20, 2014

+130561

At least one root is between 1 and 2

According to Descartes rule of signs, we have one positive root, and either two negative roots or no negative roots

Let's see...I'm going to attempt this for the first time!!

x^3 +2x^2-4 = 0

CPhillMar 20, 2014

Mar 19, 2014

+135

kat:}:
:| [size=150]a wheelbarrow can carry up to 300 pounds of weight. A bag of soil weighs 20 pounds. write and solve an inequality to represent the number of bags of soil the wheelbarrow can carry.[/size]

Hi kat:}!

Suppose we give this number of bags a name, or rather a symbol.
Let's call it n. That is the first letter of "number of bags", just to make it easy to remember.

Since 1 bag weighs 20 pounds, that means that n bags must weight n x 20 pounds.
This total weight has to be less than the wheelbarrow's capacity of 300 pounds.
We can write that as:

n x 20 <= 300

Let's write a variant of that that between [ math ] tags so that this site's calculator can solve it:

n * 20 = 300

Do you see what the maximum number of bags is that the wheelbarrow can carry?

I like SerenaMar 19, 2014

+118725

Guest:
What are the roots for P(x) = x^3 + 2x^2 -4

Are you sure the signs are right? The answer is not popping out at me!

Hint: You have to look fo an x value that will make P(x)=0

then look here
http://www.mathsisfun.com/algebra/polynomials-remainder-factor.html

MelodyMar 19, 2014

+118725

Guest:
2X, given sinX= 2/5 and cos X <0

sinx is pos therefore it is 1st or 2nd quad
cosx is neg therefor 2nd or 3rd quad
Therefore x must be in the second quadrant

sin ^-1(2/5) = 23.578.. (first quad)
X = 180-23.578... = 156.4218...
In general X=156.4218 + 360N Where N is in the set of integers

2x = 312.84...
2x = 312 degrees 50minutes and 37 seconds +720N Where N is in the set of integers (to the nearest second)

MelodyMar 19, 2014

+118725

bump

MelodyMar 19, 2014

+118725

luzmartinez:
how to do exponents

Try this
http://www.mathsisfun.com/algebra/exponents-logarithms.html

MelodyMar 19, 2014

+118725

HelpmePlease:
How can you tell if a graph is a linear function?

Rom is right of course
but
do you mean how do you tell if an equation will be a straight line?

It will have no squared terms
It will have no x*y terms
It will have no x or y in the denominators.
so it might look like

y=3x+4
2x+3y=7
5x/4 - 6x = 13/3
0.2y = 12- 0.8x
y=15

but it won't look like
xy=8
3/x=y
6x-x ²=4

I hope that helps.

MelodyMar 19, 2014

+118725

jmsylvia:
25.12/2pi

This is 25.12/2 *pi

or do you mean

25.12/(2*pi)

Either way you can do it on a calculator. there is one on this site. Look at the top of the page.

MelodyMar 19, 2014

+118725

Nobody Special:
In an arithmetic sequence a_8 = 9 and a_12 = 37. What is a_13?
Is there an equation or something that I'm missing here? Something to simplify it?

If anyone has any ideas, that would be awesome! ^_^