Step-by-step explanation:
In the 1st question
Total boxes = 6
Shaded boxes = 2
Probability = 2/6 = 1/3
Either one at any given time could be equal to zero. So
x + 2 = 0
x = - 2
x - 18 = 0
x = 18
I've enclosed a graph of this so you can see that the answers I've given are the ones expected.
A model shows the visualize of what you need to do in order to complete the problem your asked. It can also show important steps and make it easier for you to answer the question, like length×height×width.
Q20) c < 82-76
c < 6
Hope this helps