I do not understand number 11 on my assignment, the question is what is 18+5x=8x

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.

Find the power set of each of these sets, where a and b are distinct elements. a) {a} b) {a, b} c) {1, 2, 3, 4} show steps