He needs at least 2 gallons of the stain; though he will not use all of the second gallon
we have

Step 
<u>Clear the variable y</u>

Adds
both sides


Step 
<u>Convert in function notation</u>
Let


therefore
<u>the answer is</u>

Answer:
(a)r=15-b
11.9 Inches
(b)See attached
Step-by-step explanation:
Length of the candle =15 inch
Let b represent the burned length of the candle (in inches)
Let r represent the remaining length of the candle (in inches).
Therefore:
(a) r+b=15
r=15-b
When b=3,1 Inches
Remaining Length, r=15-3.1=11.9 Inches
(b)The graph showing te relationship between r and b is shown below.
r is plotted on the y-axis while b is plotted on the x-axis as labelled.
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.04/2=x/100
cross multiply and divide
it is 98% smaller than 2b.
.2b is 10% of 2b because .2 multiplied by 100 is 20 then you divide by 2 and get 10.
.2/2=x/100
it is 90% smaller than 2b.
.56b is 28% of 2b because .56 multiplied by 100 is 56 then divide by 2 and you get 28.
.56/2=x/100
it is 72% smaller than 2b.
1.8b is 90% of 2b because 1.8 multiplied by 100 is 180 then divide it by 2. you get 90.
1.8/2=x/100
it is 10% smaller than 2b.
2.5b is 125% of 2b because 2.5 multiplied by 100 Is 250 and 250 divided by 2 is 125.
2.5/2=x/100
it is 25% larger than 2b
3b is 150% of 2b because 3 multiplied by 100 is 300 and 300 divided by 2 is 150.
3/2=x/100
it is 50% larger than 2b