Simplified: 
Restrictions: x CANNOT be 0 because then the denominator would become 0 and would not be possible
We can't help unless we know what to "rewrite"
8.64 sqft
Base x Height x 1/2 = Triangle Área
4.8 x 3.6 x 1/2 = 8.64
Answer:
6.79 x 10 to the power of 3
Step-by-step explanation:
6790 divided by 1000 is 6.79
The three items cost altogether is : 111.32 + 28.75 + 73.21 = 213.28
So, he must work 213.28 : 8.75 = 24.3748571429...
Since if he works 24 hours, he wouldn't have enough money to buy the 3 items, so he must work 24 + 1 = 25 hours.
Recheck : 25 x 8.75 = 218.75 ( > 213.28)