# transform x-2y>-4?

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• Apr 2nd 2010, 01:16 PM
andrelt375
transform x-2y>-4?
solve for y, x-2y>-4(Happy)
• Apr 2nd 2010, 01:45 PM
Anonymous1
Quote:

Originally Posted by andrelt375
solve for y, x-2y>-4(Happy)

x-2y>-4
=> x+4 > 2y
=> y< (x+4)/2
• Apr 2nd 2010, 01:45 PM
pickslides
Hi there andrelt375, you now to employ your knowledge and algebra and inequalities here.

We need to isolate $\displaystyle y$

$\displaystyle x-2y>-4$

First, lets take $\displaystyle x$ from both sides.

$\displaystyle x{\color{red}-x}-2y>-4{\color{red}-x}$

Gives us

$\displaystyle -2y>-4-x$

Now we need to divide each side by $\displaystyle -2$ . When we divide through by a negative value the sign will flip the other way.

$\displaystyle \frac{-2y}{{\color{red}-2}}<\frac{-4-x}{{\color{red}-2}}$

Leaving

$\displaystyle y<\frac{-4-x}{-2}$

This can be simplified further as

$\displaystyle y<\frac{-4}{-2}+\frac{-x}{-2}$

$\displaystyle y<2+\frac{x}{2}$

And we are finished. (Hi)
• Apr 2nd 2010, 01:48 PM
Anonymous1
Quote:

Originally Posted by pickslides
Hi there andrelt375, you now to employ your knowledge and algebra and inequalities here.

We need to isolate $\displaystyle y$

$\displaystyle x-2y>-4$

First, lets take $\displaystyle x$ from both sides.

$\displaystyle x{\color{red}-x}-2y>-4{\color{red}-x}$

Gives us

$\displaystyle -2y>-4-x$

Now we need to divide each side by $\displaystyle -2$ . When we divide through by a negative value the sign will flip the other way.

$\displaystyle \frac{-2y}{{\color{red}-2}}<\frac{-4-x}{{\color{red}-2}}$

Leaving

$\displaystyle y>\frac{-4-x}{-2}$

This can be simplified further as

$\displaystyle y>\frac{-4}{-2}+\frac{-x}{-2}$

$\displaystyle y>2+\frac{x}{2}$

And we are finished. (Hi)

You accidentally flipped twice I think.