78 ≡ 2 (mod 7)
3
2√log
-10g-28f=112
24g+16f=-160
78 ≡ 1 (mod 7)
78 ≡ 0 (mod 7)
8980576÷195
lim f(x)
x->2
f(x)= $x^{2}$ -1
solve 78 is congruent to 0 (mod 7)
6786318
6786317