Slope Proof: If y = mx + b, m constant, then m is the slope

[megan0430]

Prove that if y=mx+b, where m and b are constants, then m is the slope. Write a reason to justify each step in the proof.

I'm not 100% sure what the problem is asking me to do, so please help :]

 

[galactus]

you could start with:

\(\displaystyle m=\frac{y-y_{1}}{x-x_{1}}\)

A little algbra creates the point-slope form:

\(\displaystyle y-y_{1}=m(x-x_{1})\)

You could rewrite it as:

\(\displaystyle y=mx-mx_{1}+y_{1}\)

\(\displaystyle y_{1}-mx_{1}=b=y-intercept\)

So, you have slope-intercept form:

\(\displaystyle y=mx+b\)