Question

Which expression is equivalent to a product of factors (ax – b)(ax + b) such that a and b are integers?

50x2 – 25
81x2 – 27
40x2 – 16
49x2 – 36

Answer 1

@hartnn @AriPotta @Directrix

Answer 2

since
\((ax+b)(ax-b) = a^2x^2 -b^2\)

both the first and second terms must be perfect squares

Answer 3

the same way in which both the terms in last question must be perfect cubes....here see that both must be perfect squares

Answer 4

16,25,36,49,64,81
are all perfect squares...

Answer 5

50, 27,40 are not :)

Answer 6

So A And C Are OUT

Answer 7

why is B still in ?

Answer 8

iSee iLooked At The First Number Only

Answer 9

look at both :)