How do you solve 7^(2-10r)+1=467210r+1=46?

1 Answer
Aug 20, 2016

4.376x 10^-3103

Explanation:

7^(2-10r)7210r +1=46
So 7^(2-10r)7210r =45

Remember 2^323 =8 is the same thing log_2log28 =3

So I can write the equation as :

log_7log745 =2-10r
Rearranging gives us 10r=2-log_7log745

10r =0.04376..
r=4.376x 10^-3103