John is 4 years older than his sister Mary. Together, their ages add up to 30. How old is Mary?

What is 3t+4=12+3t because this is hard

A teacher keeps track of how many books are read by students in each class. Which grade has read has read a higher rate hook per student? How many more book does the other grade need to read to have the same rate

Kyra is using rectangular tiles of two types for a floor design. A tile of each type is shown below. Which statement is correct? A.) The two tiles are similar because is 1 : 3 and is also 1 : 3. B.

If you pick a marble out of 6 red and 10 black, record its color, and return it to the bag 200 times, how many times can you expect to pick a black marble?

Automobile sales in a country were 35.9 million this year, a 2.4 % increase over last year. Find the number of auto sales in the country last year.

What type of research relies on the researcher's first-hand observations of participants in naturally occurring contexts?

720:90=72tens:9tens=

If simon makes the minimum monthly payment and makes no other charges, how many months will it be before he pays off the card? round your answer to the nearest whole month.

Y = (2) (3x^2+4x) ^4. find dy/dx

12 divided by 1/9 equals