\(7^3.98-7^3.46-52.143\\ =343.98-343.46-52.143\\ =343.\left(98-46\right)-52.143\\ =343.52-52.143\\ =52.\left(343-143\right)\\ =52.200\\ =10400\)
73.98 - 73.46 - 52. 143
= 343.98 - 343.46 - 52.143
= 343. (98 - 46) - 52.143
= 343. 52 - 52.143
= 52. (343 - 143)
= 52. 200
= 10400