Please take a look at this.

[indatshurt]

How does this:

Simplify to this?


What math skill am I lacking that is preventing me from seeing how picture 1 (top) can convert into picture 2(bottom)? Is it factoring? I can't see how the top picture turns into the bottom picture.

What should I work on that will help me see how the two images are related? On Khan Academy, the top picture converts into the bottom picture with no explanation and I'm confused as to how the top picture simplifies into the bottom picture.


Here's the full equation:


Which converts into:


As you can see, the right hand side of the equal sign is self-explanatory since you're just multiplying a fraction by it's denominator. The left side of the equal sign I'm confused about.

 

[pka]

How does this:
View attachment 26102 Simplify to this:View attachment 26103

\((x+3)\cancel{(x-1)}\cdot\dfrac{(x+4)}{\cancel{(x-1)}}=(x+3)(x+4)\)

 

[Steven G]

\((x+3)\cancel{(x-1)}\cdot\dfrac{(x+4)}{\cancel{(x-1)}}=(x+3)(x+4)\)

Is that what they call math without words? It does say it all.

 

[jalexandre]

It might help to think of it like this:

[MATH](x+3)(x-1)\frac{(x+4)}{(x-1)}=\frac{(x+3)(x-1)(x+4)}{(x-1)}[/MATH]
Now you can see more clearly that there is a shared factor of [MATH](x-1)[/MATH] in the numerator and denominator, which can be cancelled out.

 

[HallsofIvy]

Note that is true for x not equal to 1. If x= 1, that does not exist as an algebraic expression.