sam's mother is twice as old as sam. in 12 years sam will be as old as his mother was 12 years ago, how old is sam and his mother now PLZ HELP NOW

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?

The graph shows the decibel measure for sounds depending on how many times as intense they are as the threshold of sound. noise in a quiet room is 500 times as intense as the threshold of sound. what is the decibel measurement for the quiet room? 20 decibels28 decibels200 decibels280 decibels