87 deaths in 1990 and 51 in 2011. What is the percentage decrease?

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.

Solve this equation using substitution. {4x + y = −2} {4x + 6y = 44}

What is the area of the triangle 10 13 12