How do i get the solution to 3 |b-12| = |15|

How many of the 250 grandparents in the population would you expect to prefer online shopping with merchant a? merchant a: 4 merchant b: 6 merchant c: 2 merchant d: 3 other: 5 none: 5 answer choices: a.about 4 b.about 8 c.about 40 d.about 21

The longer leg of a 30-60-90 trangle is 18

What else equals 42 and 30 for multiply