Q. how many zeros does this parabola have?

2

Step-by-step explanation:

The zeros are the points on the x- axis where the graph crosses

In this case there are 2 points where the graph crosses the x- axis

These are the zeros , that is 2 zeros

x = -4

step-by-step explanation:

- 20 - 4(x + 3) = 4x

=> -20 - 4x - 12 = 4x

=> - 32 -4x = 4x

=> -32 = 4x + 4x

=> - 32 = 8x

=> -32/8 = x

=> -4 = x

they would have to work 32 hours.