Answer:
7.3 feet, 10.7 feet
Step-by-step explanation:
Using one variable and an expression, we can set the width of the two panels equal to the total width and solve:
first panel width = x
second panel width '3.4 wider' = x + 3.4
x + x + 3.4 = 18
Combine like terms: 2x + 3.4 = 18
Subtract 3.4 from both sides: 2x = 14.6
Divide by 2: x = 7.3
first panel = 7.3 feet
second panel = 7.3 + 3.4 = 10.7 feet