Question 37807
(2/3)64+(1/3)x=70 or 42 2/3+x/3=70 or x/3=70-42 2/3 or x/3=27 1/3 or x=82 

thus Jason must get at least an 82 on his final exam

proof (2/3)64+(1/3)82=70 or 42 1/3+17 1/3=70 or 70=70