One way to solve this problem is by:
First multiply both sides by 10
30r=9
Now divide by 30
r=0.3 Final Answer
28 is the answer rrrrrrrrrrrr
The number in brackets represents the percentage change
1.045
the 1 shows that it is an increase and the .045 shows the percent
for example 1.55 would be 55% increase and 1.555 would be 55.5% increase
To find this answer, we need to multiply 3.57 by 12.

Therefore, 12 planks will cost $42.84.