Take the cube root of each side: 2x=cuberoot(113)=4.8346 (approx), so x=4.8346/2=2.4173. To find the cube root of 113, you can use logs (base 10) if your calculator cannot work out 113^(1/3): simply find log(113) and divide it by 3, then raise 10 to the result (there's probably a 10 to the xth power key on your calculator).