When you think about it, X = sqrt(y) is actually a very simple parabola.

X = sqrt(y)

X^2 = (sqrt(y))^2 ...... square both sides

Y = X^2 .....................simplify 

5(2x-8) can be expanded by multiplying each part by the 5.

5(2x-8) = 5*2x + 5*(-8) = 10x - 40.

Alternately, if you are asked to factorise 5(2x-8), you should look for common factors. 2 is the highet common factor of 2x and -8.

5*(2x-8) = 5*2*(x-4) = 10*(x-4)

See that when we factorise 10x - 40, it also becomes 10(x-4). The highest common factor of 10x and 40 is 10.

10x - 40 = 10*(x-4)

I believe this is simply a substitution question; the formula may just be something to plug values into.

$\text{Wind Chill} = \text{Temperature} \times \frac{4}{25}$

$\text{Wind Chill} = 20 \times \frac{4}{25}$

$\text{Wind Chill} = \frac{80}{25}$

$\text{Wind Chill} = 3\frac{1}{5}$

3.2 degrees Fahrenheit 

-14 + 2 = -12

If you want another way to look at it you could think of it like:

14 - 2 = 12, then switch the sign to be -12

EDIT: Woops Dragonlance is correct my answer should go like this. 

$4a^2-4a+1-6a^2-28\textcolor{red}{+}2a^7=0$

$2a^7-2a^2-4a=27$

Or is the general form this?

$2a^7-2a^2-4a-27=0$

On a different note can you still edit your previous posts? 

ha we both got to the same point and couldn't do it :)

Polynomials comes to mind but I haven't learnt that yet.

Assuming it is equal to 0...

$(1-2a)^2/6-a^2-(14-a^7)/3=0$

$(1-2a)(1-2a)/6-a^2-(14-a^7)/3=0$

$(4a^2-4a+1)/6-a^2-(14-a^7)/3=0$

$4a^2-4a+1-6a^2-2(14-a^7)=0$

$4a^2-4a+1-6a^2-28-2a^7=0$

$2a^7+2a^2+4a=-27$

... but from here I'm not sure what to do

$$(5x^2+4y)^2 =$$

$$(5x^2+4y)\times{(5x^2+4y)} =$$

Using FOIL:

$$(5x^2\times{5x^2}) + 2(5x^2\times{4y}) + (4y\times{4y}) =$$

$$25x^4 + 40x^2y + 16y^2$$

ooops I just realised the question may have been x * y = 48 and x/y=3 :P

Probably a more conventional way of looking at it.

In that case nice job Rosala!... although if x is 4 and y is 12 then does x/y = 3? I think they may need to be the other way around.

:D 

x * y = 48 x / y = 3

We can solve this using simultaneous equations:

(1)....x*y = 3

48x/y = 3

48x = 3y

(2).....y = 16x

Sub (2) into (1)

x*16x = 3

16x^2 = 3

x^2 = 3/16

x = √3/4

To find y sub x=[√3/4] into (1)

(√3/4)*y = 3

y = 3/(√3/4)

y = 3*(4/√3)

y = 12/√3

y = (12*√3)/3

y = 4*√3

To check:

$$\frac{\sqrt{3}}{4}\times({4}\times{\sqrt{3}})$$

$$\sqrt{3}\times{\sqrt{3}}=3$$

Sorry for my very crude maths. I also believe thare are probably other solutions, as I did not explore the negative root of (3/16) being equal to x.

What you have, 0.92, would be correct if we were rounding to 2 decimal places.

We need the number rounded to 4 decimal places. 

To do this lets look at the first 5 decimal places:

0.9174311926605504587155963302752293577981651376146788991

If the fith decimal place is a 0,1,2,3 or 4, the 4th digit stays the same (called rounding down). If the 5th digit is a 5,6,7,8 or 9, the 4th digit is rounded up by 1.

For example, if the number was 0.91748, the result when rounded to 4 decimal places would be 0.9175 (note there are 4 digits after the decimal point.

When looking at your number we can see that because the 3 is below 5, the number should be rounded down, resulting in 0.9174

I hope this helped and that it wasn't too longwinded :)

2 - (7x + 5) = 13 - 3x.......Expand the brackets

2 - 7x - 5 = 13 -3x..........Group like terms

-7x - 3 = -3x + 13

-16 = 4x........................Divide both sides by 4

x = -4

(Fixed!  )

7 + (7/7) + (7*7) -7 ...... first lets get rid of the two sevens (+7 -7 = 0)

7/7 + 7*7  ............... lets simplify these terms (7/7 = 1, 7*7 = 49)

1 + 49

50

Good point I did wonder if I was overcomplicating it a little. It's just how I go through it in my head.

This is an example of applying the minus sign to everything enclosed in the respective brackets.

-(22 - 18) can also be written as -1*(22-18).

83 - [59 - (22 - 18)]

83 -59 +(22 - 18)

83 -59 +22 -18

I think you can do the rest :)

Fructose: 38.5% of 1kg = 385g

Glucose:  31.0% of 1kg = 310g

$$\frac{5}{8}-\frac{1}{2}$$   (To subtract make the denominators the same)

$$\frac{5}{8}-\frac{4}{8}$$

$$\frac{(5-4)}{8}$$

$$\frac{1}{8}$$

-5 + 2(3x - 4) -1 [expand]

-5 + 6x -8 -1  [group like terms]

6x - 14