Answer:
A book is worth $1 and a DVD is worth $12.
Step-by-step explanation:
The equations (2 unknowns and two equations, d is for a DVD and b is for a book):
For David: 3d+4b=40
For Anna: d+6b=18
Now multiply the second equation with -3 and add to the first equation:
3d+4b=40
−3d−18b=−54
Combined equation: −14b=−14 and b=1 (means that each book is worth $1).
Now for DVD price, use the second equation:
d=18−6 or d=12 (means that each DVD is worth $12).
A book is worth $1 and a DVD is worth $12.
I believe that x is equal to 6. x=6
The graph of f(x) opens upward
For the values of x < -5 the function is a line with negative slope, for the values of x > - 5 the function is a line with positive slope.
The two lines intercept in the point (-5,-2). That is the vertex of the function; a minimum value. So, all the other points are above the line y = -2.
It is 3/10 because 10 is bigger than 5
