Answer:
r= 7.14 (rounded to 2 decimal places)
Step-by-step explanation:
We have to solve this equation for the value of r. We will use distributive property and basic algebra to solve this.
Distributive property is a(b+c) = ab + ac
Now, the steps of solving are shown below:
Hence, value of r is 7.14 (rounded to 2 decimal places)