Try this solution:
1. rules:

2. according to the rule described above:
I think this is correct-scroll down through the picture
Step-by-step explanation:
You would solve it by turning it into a equation and solving it. You would place the dots on the graph and put them in the points where they are supposed to go.
Step-by-step explanation:
22+2x+8= x+20
2x+30=x+20
x+30=20
x=-10
answer is -10
Question:
What is the equation for the following statement,"One-half of a number decreased by 3 is 21.
Answer:
<em>half the number = x/2 </em>
<em>decreased by 3 </em>
<em>(x/2) -3 =21</em>
<em>=48</em>