I am stuck at this question.
A battery of 9 V charges a capacitor of 47 uF through a resistor.
What resistor value needs to be used to obtain a voltage across the
capacitor of 8 V when 10 seconds have elapsed? You will need to
obtain the standard equation for the voltage across the capacitor
charging in this circuit configuration. You must show the theoretical
calculations you did to get the result.

I have done some calculations but I seem to be getting the wrong answer.

here is my working out
10 s. =10,000mS.
X = t/RC, Vr
= 9/eᶺx
= 9-8
= 1,
eᶺx
= 9, X
= 2.197
= 10,000/(R*47), 2.197
= 213/R, 2.197R
= 213, R
= 96.8Kohms.