Let
x---------> the regular price of the jeans
we know that
[tex]x*0.40=\$20[/tex]
Solve for x
Divide by [tex]0.40[/tex] both sides
[tex]x*0.40/0.40=\$20/0.40[/tex]
[tex]x=\$20/0.40[/tex]
[tex]x=\$50[/tex]
therefore
the answer is
the regular price of the jeans was [tex]\$50[/tex]