Melody

Thanks asinus :)

$249-%15

Do you mean

$249 - 15% of $249   ?????

249-0.15*249 = 211.65

Hi. Olivia :)

4=6+x

Is the same as

X+6=4

You need to get rid of the 6 to get x by itself.

-6 will work.

But if you -6 from the right side you must -6 from the left side too.

X+6-6=4-6

X= -2

Check

X+6=4

-2+6=4   yes it does !!   :D

Yes - Good work Max :))

hello can u give me some tips how to easily calculate for example x=log(1/16)2 i know its (1/16)^x = 2 but i dont know how to calculate that x

\(x=log_{(1/16)}2\\ \left(\frac{1}{16}\right)^x=2\\ \left(\frac{1}{2^4}\right)^x=2\\ \left(2^{-4}\right)^x=2^1\\ 2^{-4x}=2^1\\ -4x=1\\ x=\frac{-1}{4}\\~\\ or\\ x=log_{(1/16)}2\\ \left(\frac{1}{16}\right)^x=2\\ log_{10}\left(\frac{1}{16}\right)^x=log_{10}2\\ xlog_{10}\left(\frac{1}{16}\right)=log_{10}2\\ x=log_{10}2 \div log_{10}\left(\frac{1}{16}\right)\\ \)

(log(2)/-1.2041199826559248) = -0.25

           10
find      ∑ (k+2)*3*2^k
         k=0

\(\displaystyle\sum_{k=0}^{10}\;\;3(k+2)*2^k\;\;\\ =3*\displaystyle\sum_{k=0}^{10}\;\;(k+2)*2^k\;\;\\ =3[(2)+(3*2)+(4*4)+(5*8)+(6*16)+(7*32)+(8*64)+(9*128)+(10*256)+(11*512)+(12*1024)]\)

=67584 

Who am talking to?    You should get an account and then you could private message me. :)

At present I am listening to this:

Mmm 

what are the roots of y=2x times 2x-7x-4

Do you meant the roots of

\(y=2x\times(2x-7x-4)\\ y=2x\times(-5x-4)\\\)

Roots are when y=0

so  2x=0     or      -5x-4=0

        x=0     or         x=-4/5