Justin can type w words per minute. We can write this expression as (for the total words typed in a period of time at a rate of w):
[tex]J\text{ = w}\cdot x[/tex]
Melvin can type 4 times as many words as Justin. The expression can be written as:
[tex]M=4w\cdot x[/tex]
For example, if we have 3 minutes. Justin type 30 words per minute. Then, Melvin will type 4*30=120 words per minute. Or:
[tex]J=30\cdot3=90,M=4\cdot30\cdot3=360[/tex]
Justin will type 90 words in three minutes, while Melvin will type 360 words in 3 minutes.
The number at the side of x is the rate at which both, Justin and Melvin, type words per minute (w and 4w).
Therefore, the expression at which Melvin can type can be:
[tex]M=4w\cdot x[/tex]
At a rate of 4w, to find the total words typed in a period of time.
