Answer:
$70 is the regular price of the shirt.
Step-by-step explanation:
One way in which to find the regular price here is to write the equation
0.60s = $42. A 40% discount is reflected in 100% - 40%, or 1.00 - 0.40, which comes out to 0.60.
If 0.60s = $42, then the regular price of the shirt is
s = ($42)/0.60 = $70
