Answer:
10
Step-by-step explanation:
First, multiply everything in the parentheses.
Next, subtract 21x from both sides to get all the variables on one side.
Next, add 16 to both sides to get all the real numbers on one side
Finally, divide both sides by 30 so we can get the variable by it's self
Answer:
third choice is the answer r is greater than or equal to 46
To find the answer you simply find the square root of -169 which is 13 so x=13