If this is just an expression, then all you have to do is combine like terms, or groups of numbers and variables that have the same variable.
When simplified, you get the equation
-12+ 16r or
-18+6+3r+13r=16r-12
B. Accuracy is if it's right or not. Precision is how many decimal places it goes out to. So it is precise but not accurate.
V solid = π *

* 13 / 3 + π *

* 2 = 3.14 * 25 *13 / 3 + 3.14 * 50 = 340.16 + 157 = 497.16 ≈ 497.20 cubic centimeters;
Answer: To figure out the tip, you need to find 20% of $52.60.
0.2×52.6=10.52
Step-by-step explanation: