Question

Which expression is not equivalent to 1/343

A 7^4 * 7^-7
B 7^7 * 7^-10
C 7^-2 * 7^-5
D 7^-5 * 7^2

Answer 1

I would say that c is not equal to 1/343

Answer 2

c is not equivalent to 1/343

(7−2)(7−5)

=7−2*7−5

=(1/7*7)*(1/7*7*7*7*7)

=1/7*7*7*7*7*7*7

=1/77

=1/823543