<p>Table
X 0 1 2 <----- table
Y 10 a b<br>
if y-1 is directly propotional to X+1
what is the value of b-a ?</p>
<p>Is b-a equal to 10?</p>
<p>is the answer 9?</p>
<p>The correct answer is 9.</p>
<p>If y-1 is directly proportional to x+1 then,</p>
<p>y-1=k(x+1)</p>
<p>Substituting the (x,y) value from the table yields,</p>
<p>10-1=k(0+1)
k=9</p>
<p>Now we have the formula: y=9x+10
a = 9(1)+10 = 19
b = 9(2)+10 = 28</p>
<p>b-a = 28-19 = 9</p>
<p>thx for explantion
the answer is 9 :)</p>