Hi there!
Here are the important information we know:
Shorter movie duration + Longer movie duration = 4hours (= 4×60 = 240 min.)
Shorter movie duration = X
Longer movie duration = X + 30 (Because half 1hour = half 60min = 30min.)
Now that we have written down everything we know, we need to write down an equation that, when solved by isolating "X", will give us the duration of the shoter movie :
Shorter movie + Longer movie = 240 minutes
X + (X + 30) = 240
Subtract "X" from each side of the equation → 240 - X = 240 - X
X + 30 = 240 - X
Subtract 30 from each side of the equation → 240 - X - 30 = 210 - X
X = 210 - X
Add "X" to each side of the equation → X + X = 2X
2X = 210
Divide each side of the equation by 2 → 210 ÷ 2 = 105
X = 105
This means that the shorter movie lasted 105 minutes.
Divide 105 by 60 to find the number of hours :
105 ÷ 60 = 1.75 → 1hour
0.75 × 60 = 45 → 45 minutes
The answer is : The shorter movie lasted 1hour and 45 minutes.
There you go! I really hope this helped, if there's anything just let me know! :)
