Question

calculati dand factor comun (7 la puterea 10-7 la 9)/ (7 la 9- 7 la 8)

Answer 1

$\frac{7^{10}-7 ^{9} }{7 ^{9}- 7^{8} } = \frac{7 ^{9}(7-1) }{7 ^{8}(7-1) } = 7 ^{9} :7 ^{8}=7 ^{9-8}=7$