PLEASE ANSWER FIRST QUESTION WILL GIVE BRAINLESS IM GONNA FAIL

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

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.

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 + 4x + 5 = 0