The radius would be 9 using the formula C=2r
Odd no. 3/6 = 1/2
less than 4 3/6 = 1/2
The answer is -7
2x-3(x+4)=-5
Multiply by -3
2x-3x-12=-5
Collect like terms
-x-12=-5
Move constant to the right to change its sign
-x=-5+12
Add
-x=7
Change the signs
x=-7
Hope this helps.
If not, go to: https://www.mathportal.org/calculators/financial-calculators/simple-interest-calculator.php