2.) A bookshelf contains seven math textbooks and three science
textbooks. If two textbooks are drawn at random without replacement,
what is the probability both books are science textbooks? *
A)1/15
B)3/10
C)3/7
D)1/2

A

Step-by-step explanation:

the probability of the first book being science is (science books/total books)

there are 3 science books and 7 + 3 = 10 total books

so the probability the first time is 3/10

if you pick a science book the first time and don't replace it, the number of science books drops to 2, and the total books drops to 9

so the probability the second time is 2/9

now multiply these two values to find the probability of both being science books

3/10 x 2/9

= 6/90

= 1/15

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!