Thanks Heureka,

I have interpreted this question the other way around I think.  

I think the wording is very poor.

Even so I need to think about it.

Since your answer is the same as the 'book'.  It is obviously the interpretation that they wanted. :/

Ah yes, so the trinomial was right but the quadratic comes from the term being squared not the four terms in two brackets as I thought. So I would say the question you have set below is a quadratic trinomial.

Let's try this one;

x²-x-6     Not too difficult

= (x-3)(x+2)

= x²+2x-3x-6

= x²-x-6

It is not 3.5 it is 3/2  which is 1.5

Wouldn't 3.5 be more like 7/2?

In that case the result would be 21.

Yes fair enough :)

X^2+7x=18

$$x^2+7x-18=0 \qquad (x-2)(x+9)=0\qquad x_1=2 \quad x_2=-9$$

That's definitely a lot simpler Melody, but I was going for a fraction as requested, not a mixed fraction.

Depends what the poster wanted, but now they have both so should be happy, hopefully.

In a factory, we know that 20% of produced goods will be replaced. How many products will have to be produced to the warehouse, so that 10 000 orders and the replacements can be sent be with probability of 0.9 ? The answer is 12 051, but I dont know how to calculate it, or even understand the question properly

$$\small{\text{binomcdf$\ (10000,0.2,\textcolor[rgb]{1,0,0}{2051}) \\\\
= \sum \limits_{i=0}^{\textcolor[rgb]{1,0,0}{2051}} \binom{10000}{ i}*0.2^i*0.8^{(10000-i)} =0.9008 \\
$
}}$$

@@ End of Day Wrap   Thurs 22/1/15     Sydney, Australia      Time 10:20 pm

Hi all, 

Today our wonderful answerers were Sasini, CPhill, Geno3141, Tetration, Lemoncrush14, Tenacious, Happy7, eli101, Fieldmouse830, Saseflower and Heureka.  Thanks you  

I would really like people to suggest interst posts for the wraps.  You can just send the addresses to me via private message.  I would really like that.   

Interest posts:

1)  Why isn't anyone answering our questions     

Fri 23/1/15

CONGRATULATIONS TO HEUREKA

Heureka is now on the Top Answerers Board !!!   I am so pleased.  

Heureka you are an extremely valued member of our answer team.    

A puzzle      Thanks Chris

I've started answering it.  Now I have asked you to try the next bit.  

is no one going to answer this?

Let one of the angles be x and the other by 17x

x+17x=90

now solve :)

You start by taking it all to one side 

$$\\X^2+7x=18\\
X^2+7x-18=0$$

now I would like either the question asker or Tenacious to factorize the left hand side for mw please.

Hint1:  You need 2 numbers that mult to -18 and add to +7 

Hint2:  What will the signs of these numbers be?

Well there is an infinit number of solutions if there are no restrictions on the domain.

There is one in the first  quad and one in the second quad but you can add 360n degrees or 2npi radians 

where n is any integer.

[1 + 6/13]  - 18/19

19/13 - 18/19 =      (the common denominator = 247)

[361 - 234] / 247 =

127/ 247

1 and 6 over 13 minus 18 over 19=1(6/13)-(18/19)=-120/247

guess i'm wrong again

*sigh

I assume this is (3^2)^x = 195  ??? if so, we have

9^x = 195     take the log of both sides

log 9^x  = log 195   and by a log property, we have

x log 9  = log 195    divide both sides by log 9

x = log 195 / log 9  = about 2.4

We don't see anything, here......(????)

find the slope of the line that passes through the points (4,5) and (11,8)

slope = $$\small{\text{
$
\frac{8-5}{11-4}=\frac{3}{7}=0.42857142857
$
}}$$

Actually, there are two solutions.

You can use equation:

sin(x)^2 + cos(x)^2 = 1

Just solve cos(x).

HAHAHAHA !!!

I beat you, heureka  !!!

LOL !!!!