The approximate linear equation of the graph below is y = 4 x + 55.  Which interpretation of the y-intercept is correct?

 

A. A student can receive a 55% for studying for 4 hours.

B. A student can receive a 55% without studying.

Let K(t) be a measure of the knowledge you gain by studying for a test for t hours. Which do you think is larger, Is the graph of K concave upward or concave downward? Why?

In 2018, North Carolina spent 9.528 x 10^3 dollars on each student in public schools. There were about 1.5 x 10^6 students in North Carolina public schools in 2018. What was the approximate total amount spent on North Carolina public school students in 2018?

Solve the system of equations and give a geometrical interpretation of the result.
x + y + z = 6
2x + y − 3z = -5
4x − 5y + z = −3