Well, it's 40/4 for one minute, or 10 for one minute. You want 36 mins, so you multiply by the square root (6), to get $60, to which you also add the $90 for the lesson (result is $150)
Move the decimal 2 places to the right
8.4 becomes 840
A mixed number and one and two-ninths.
Hope this helps! :D
Answer:
You did not post the options, but i will try to answer this in a general way.
Because we have two solutions, i know that we are talking about quadratic equations, of the form of:
0 = a*x^2 + b*x + c.
There are two easy ways to see if the solutions of this equation are real or not.
1) look at the graph, if the graph touches the x-axis, then we have real solutions (if the graph does not touch the x-axis, we have complex solutions).
2) look at the determinant.
The determinant of a quadratic equation is:
D = b^2 - 4*a*c.
if D > 0, we have two real solutions.
if D = 0, we have one real solution (or two real solutions that are equal)
if D < 0, we have two complex solutions.
