find e,f,g,h

eg = 45 ... (1)
eh = 80 ... (2)
fg = 70 ... (3)
fh = 56 ... (4)
(1)/(2) => g/h = 45/80
g = 9h/16 ... (5)
(3)/(4) => g/h = 70/56
g = 5h/4 ... (6)
Since e,f,g,h cannot be zero, (5) & (6) are inconsistent result => there is no solution

(1)x(2)x(3)x(4):
(efgh)^2=9x5x16x5x7x10x8x7
efgh=3x5x4x7x4 √5......(5)

但(1)x(4):
efgh=2520.........................(6)
(5)<>(6)
故無解!