Paul is 12 years older than Colin. Caroline is 3 years younger than Colin. If the total of their ages is 87, how old is the youngest of them?

23

Step-by-step explanation:

87=x+(x+12)+(x-3)

87=3x+9

3x=78

x=26

This is Colin's age. Caroline is 3 years younger than Colin, so she is the youngest, and we need to find her age. Subtract 3 from 26, and you get your final answer, 23.

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!