Which of the following numbers is a factor of 78? Choose 1 answer :

A- 7

B- 4

C- 6

D- 9

Step-by-step explanation:

78 = 2 * 39 = 2 * 3 * 13.

Since 6 = 2 * 3 and its factors can be found in 78,

Hence the answer is 6. (C)

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is:

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!