Answer:
Return trip travel time: 7h
Step-by-step explanation:
Let d be the distance.
Index 1 refers to initial trip, index 2 refers to the return trip.
v1=70mi/h
v2=40mi/h
t2=t1+3h, or t1=t2-3h (travel times)
d=v1×t1=v2×t2
v1×(t2-3)=v2×t2
v1 t2 -3 v1=v2 t2
v1 t2 - v2 t2=3 v1
t2(v1-v2)=3v1
t2=3v1/(v1-v2)
Or
t2=3×70/(70-40)=3×70/30=7h
Answer: The domain is all real numbers
I can't say that the y intercept is 3 because when you distribute,
It seems like the y intercept is 24.
3) x² - 121 = 0
x² = 121
x' = +√121
x' = 11
_______________
x'' = - √121
x'' = -11
Solution ⇒ S{-11 ; 11 } or (x-11)(x+11)
4) 4x² + 144 = 0
4x² = -144
x² = -144 / 4
x² = -36
x = √-36
No solution ⇒ S = ∅
5) z²+10z+21 = 0
Δ = 10² - 4(1)(21)
Δ = 100 - 84
Δ = 16
x' = (-10+4) / 2 = -6/2 = -3
x'' = (-10-4) / 2 = -14/2 = -7
Solution ⇒ S{ -7 ; -3} or (x+3)(x+7)
So first find time elapsed
10:40-11:40=1
11:40-12:40=1
12:40-1:10=0.5 or 30 mins
so add
1+1+0.5=2.5, 2 hours 30 mins
3 miles per hour
3 times numberof ohours
3 times 2.5
7.5
answer is 7.5 miles
