Answer:
84 dollars
Explanation:
use x to represent the amount of money Laura had when she started shopping.
use y to represent the amount of money she had left after buying a pair of shorts.
You can create these two equations:
3/4x=y
2/3x=42
now, subsitute the value of y into the second equation.
2/3(3/4x)=42
1/2x=42
x=84