Whats they answer for they question 10+20

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.

On #16 : explain how factoring a trinomial, ax^2+ bx+ c, when a does not equal 1 different from factoring a trinomial when a = 1.

Identify the slope an intercept of the following linear equation y = 1/5x - 6 a. slope: 1/5; intercept: -6 b. slope: 5; intercept: -6 c. slope: -1/5; intercept: 6 d. slope: 1/5; intercept: 6