Answer:
The Multiplication property
Step-by-step explanation:
The Multiplication property by a constant was used
For real numbers a and b, and c different from zero:
If c is positive and [tex]a <b[/tex] then [tex]a*\frac{1}{c} <b*\frac{1}{c}[/tex].
If c is negative and [tex]a <b[/tex] then [tex]a*\frac{1}{c} >b*\frac{1}{c}[/tex].
In this case we have
[tex]5x<100[/tex] Then [tex]\frac{5}{5}x<\frac{100}{5}[/tex]
Finally
[tex]x<20[/tex]