Kali left the white house and traveled toward the lake. ndiba left one hour later traveling 15 mph faster in an effort to catch up to her. after two hours ndiba finally caught up. what was kali's average speed? the answer is 30 mph but i have no idea how to get there. ! all i have so far is this: n = k + 15is that even correct?

The speed of Kali is 30 mph.

Step-by-step explanation:

Let, the speed of Kali be "x", then speed of Ndiba will be:

Speed of Ndiba = x + 15 mph

If, the time for travel for Ndiba is 2 hrs, when he catches Kali, and he left 1 hour later than Kali, then then time traveled by Kali at that instant will be 2+1 = 3hrs.

At the point of meeting both will have covered same distance.

Distance Covered by Kali = Distance Covered by Ndiba

(Speed of Kali)(Time traveled by Kali) = (Speed of Ndiba)(Time traveled by Ndiba)

(x)(3) = (x +15)(2)

3x = 2x +30

x = 30 mph

The correct answer is, actually 30 mph, by the solution shown above.

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!