Which of the following is NOT a reason why the Europeans colonized Africa? I need help please please!?

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite

Based on what you know about the location of the earth in relation to the sun, why is this called the goldilocks zone in other galaxies?

Find the coordinates of a if b(-9,-10) is the midpoint of ac and c has the coordinates of (-1,9)