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:
[tex]-3r-8(8r+8)=-9(-4+9r)\\-3r -64r-64=36-81r\\-67r-64=36-81r\\-67r+81r=36+64\\14r=100\\r=\frac{100}{14}\\r=7.14[/tex]
Hence, value of r is 7.14 (rounded to 2 decimal places)