what should we multiply the top equation by to be able to cancel out the y and solve by elimination? 7x+2y=24 and 8x+2y=30

At the school fair, grade 3 raises 84 more then grade 4. grade 4 raises 112 more then grade 2. grade 3 raises 360. how many dollars does grade.2 have

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.