He lifts for 11 more minuets each day.
51 + 11 = 62
He lifted for 62 minuets on Friday.
62 + 11 = 73
He lifted for 73 minuets on Saturday.
First we must convert these mixed numbers to improper fractions:


So then we need the product of these two numbers. That means to multiply:

But then we need the value of half of this product. So then let's multiply by one-half:

Then we can convert this from an improper fraction to a mixed number:

And so this number is half of the product of the initial two numbers.
Answer:
x = 98°
Step-by-step explanation:
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
x is an exterior angle and 53° and 45° are the opposite interior angles, hence
x = 53° + 45° = 98°