Answer:
71.51
Step-by-step explanation:
A=ah+bh+ch+1
2﹣a4+2(ab)2+2(ac)2﹣b4+2(bc)2﹣c4=3·3+7·3+7·3+1
2·﹣34+2·(3·7)2+2·(3·7)2﹣74+2·(7·7)2﹣74=71.51219
