Melody

At present you have 2 litres of salt in 8 litres of water   which is 2/10 = 0.2 = 20% saline

I want to know how much water I need with 2 litres of salt to get  5% salinity

Let the TOTAL amount of solution be x litres

2/x = 0.05

2/0.05 = x

x=40 litres

But 2  we already have 10 litres of that so we need to add 30L of water.

check

2/40 = 0.05 = 5%

You might find that someone can explain this more simply than me.

7^0=   01

7^1=   07

7^2=   49

7^3= _43

7^4= _01

7^5= _07

7^6= _ 49

7^7= _43

7^8= _01

etc

Now we have the pattern   07,49,43,01, .........

2011/4 has remainder 3      so it will end in 43

So far they have played 80% and won 40% of those that is 0.8*0.4 = 32% won so far

32% + 20% of x% = 50%

0.32 +  0.2*0.01x = 0.5

0.002x = 0.5-0.32

0.002x = 0.18

x= 180/2 = 90

So we must win 90% of the remaining games.

4ac2 10d2x2 5x 12a2c2

Do you mean

4ac^2 *10d^2x^2 * 5x * 12a^2c^2    ?

You need to learn to use the hat ^ symbol for powers.

which is

\(4ac^2 *10d^2x^2 * 5x * 12a^2c^2\\~\\ =4*10*5*12 * a^1\;c^2\; d^2\;x^2\; x \;a^2\;c^2\\~\\ =4*10*5*12 * a^3\;c^4\; d^2\;x^3\\~\\ =2400\; a^3\;c^4\; d^2\;x^3\\~\\ \)

\(x^2+y^2 - 6 = 6x + 2 y\\ (x^2-6x)+(y^2-2y)=6\\ (x^2-6x+9)+(y^2-2y+1)=6+10\\ (x-3)^2+(y-1)^2=4^2 \)

the radius is 4 units

This question has already been answered this morning.

You are the one who did the nice work Catmg.  

Yes school is busy, so is life for younger people.

Most of the people who are here a lot, to answer questions I mean, are retired.

It can continue to be a nice hobby for you though :))

I find it quite difficult to get my head around geometry questions such as this.

So I will give you some insight as to how I go about it.

I drew the diagram and shade the smaller one.

then I said the smallest side of the big triangle is AC which corresponds to the smallest side of the small diagram AD

then I said the biggest side of the big triangle is AB which corresponds to the biggest side of the small diagram AC

Now I draw the corresponding triangles like this:

And then I take it from there.

I suppose it is too slow long term but while you are getting the hang of it it can help.

I get 28 degrees.  (which I have not checked)

Let's see what catmg comes up with.