Ik why i got a.) wrong but i need help why the answer for b.) is $1,000 also whats the answer for letter C.

What is f(3) for the quadratic function f(x)= 2x^2+ + x - 12

An an average person has 6×10 by the power of two as many red blood cells as white blood cells a small sample of the blood has 7×10 by the power of three white blood cells about how many red blood cells are in the sample

Bradley hikes 12 miles in 3 hours. in relation to bradley’s hike, which statement describes the expression