Answer: 40
Step-by-step explanation:
Step-by-step explanation:
we simply need to get the total distance and the total time and put them into relation, norming it to distance in 1 hour. after all, speed is always an average number over a period of time (even if it is a tiny period of time).
the total distance is
72 + 69 = 141 km
he drove 69 km going 60 km/h.
how much time did he need ?
we need to get the hours out of an expression of km and h.
so, we need to do
69 km × 1/60 km/h = 69 h / 60 = 69 minutes = 1.15 hours =
= 1 h 9 minutes
so, the total time was
48 + 69 = 117 minutes = 117/60 = 1.95 hours
the average speed for the whole trip was then
141 km / 1.95 h = 141/1.95 km / 1 h = 72.30769231... km/h
5(x-2)(x+4)>0 For this to be true, both parenthetical terms must be both positive or both negative.
x<-4 and x>2
x=(-oo,-4),(2,+oo)
The first two are equivalent to 15 = k + 13
8 = k + 13 - 7 → ( add 7 to both sides )
8 + 7 = k + 13 ⇒ 15 = k + 13 ' is equivalent '
12 = k + 13 - 3 → ( add 3 to both sides )
12 + 3 = k + 13 ' is equivalent '
