A boy standing on the shore of a lake 1 mile wide wants to reach the fast-food restaurant 3 miles down the shore on the opposite side of the lake. If he swims at 2 mph and walks at 4 mph, is it quicker for him to swim directly across the lake and walk to the restaurant or to swim directly to the restaurant? How much quicker? Explain.

the size of the resulting matrix is 1-by-3.

step-by-step explanation:

the size of the two matrices given are as follows:

no .of rows of matrix 1 = 1

no .of columns of matrix 1 = 3

no .of rows of matrix 1 = 3

no .of columns of matrix 1 = 3

to find the size of the resulting matrix without actually solving the multiplication of the matrix, this is what you do:

if resulting matrix = matrix 1 * matrix 2

no. of rows of the resulting matrix = number of rows of matrix 1

no. of columns of resulting matrix = number of columns of matrix 2

note: the order of the matrices matter!

the answer is; biodiversity resulting from few ancestors

adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. the parts of the population in the different ecologies begin to adapt to their local environments. due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. they, therefore, diverge to different species sharing a common ancestor.  

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!