Need answers ASAP please all answers are greatly appreciated!

Each month, a shopkeeper spends 5x + 14 dollars on rent and electricity. if he spends 3x−5 dollars on rent, how much does he spend on electricity? for which value(s) of x is the amount the shopkeeper spends on electricity less than $100? explain how you found the value(s).

Nikolas calculated the volume of the prism. his work is shown below.

In the diagram below de and ed are tangent to 0 which expression gives the measure of def