Marla says that every number in nineties is composite. jackie says that one number in the nineties is prime. who is correct?

Jackie, 91, 97 is prime.

Step-by-step explanation:

Remember that a number greater than 2 is NOT prime if it is divided by any  number different than 1, for example 6 is NOT prime because 3 divides 6. 7 is prime because the only divisors of 7 are 1 and 7.

So for the nineties 90 is divisible by 45.

91 is divisible by 7

92 is divisible by 2

93 is divisible by 3

94 is divisible by 2

95 is divisible by 5

96 is divisible by 2

97 IS PRIME, is just divisible by 1 and 97

98 is divisible by 2

99 is divisible by 3

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hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!