Mrs. Larson, the science teacher, collected 18 sedimentary rocks and 12 metamorphic ones. Now she wants to create some identical kits for studying rocks, without having any rocks left over. What is the greatest number of kits she can create?

The greatest number of kits she can create is 6 kits

Step-by-step explanation:

We can solve the above question using the greatest common factor method.

We have to find the factors of 18 and 12

The factors of 12 are: 1, 2, 3, 4, 6, 12

The factors of 18 are: 1, 2, 3, 6, 9, 18

Then the greatest common factor is 6.

Therefore, greatest number of kits that she can create is 6 kits

The number of sedimentary rocks in each kit

18 sedimentary rocks /6 kits = 3 sedimentary rocks

The number of Metamorphic rocks in each kit =

12 metamorphic ones/ 6 kits = 2 metamorphic rocks

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!