What is
8631788 to the nearest 100

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).

Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great

2f(x)= x+3 if 4 < x < 8 2x if x 28 2