Speed (S) = Distance (D) / time (t)
First stretch
45 = D / 2
D = 45*2
D = 90 mp
How is the same distance:
Second stretch
S = 90 / t
Average speed (AS):
AS = (S1+S2) / 2
60 = [45+(90/t)] / 2
120 = 45+90/t
120-45 = 90/t
75 = 90/t
t = 90/75
t = 1,2 h
________________________
And now:
S = 90 / t
S = 90 / 1,2
S = 75 mph
Answer:
nth=a+(n+1)d
Step-by-step explanation:
Answer:
x+21 y
Step-by-step explanation:
Answer: T=1/2 Y + -5/2
Step-by-step explanation:
y=2t+5
2t+5 +-5= y +-5
2t=y-5 2t/2=y-5/2
t=1/2y+-5/2
= t=1/2y + -5/2
Answer:
The two numbers are:
30 and 18
Step-by-step explanation:
a + b = 48
a - b = 12
From the first eq.
a = 48 - b
Replacing this last value in the second eq.
(48 - b) - b = 12
48 - 2b = 12
48 - 12 = 2b
36 = 2b
36/2 = b
18 = b
from the first eq.
a + 18 = 48
a = 48 - 18
a = 30
Check:
from the second eq.
a - b = 12
30 - 18 = 12
