Slope of AD = (2k - 0)/(2j -b - 0) = 2k/(2j - b)
slope of BC = (2k - 0)/(2j - b) = 2k / (2j - b)
AD ║ BC (same slope)
Slope of AB = 0
Slope of DC = 0
AB║DC
Answer:
86
Step-by-step explanation:
A+b+c=28x+40=180
—>28x=140
—>x=140/28=5
c=9x-3
—>c=42
Answer: He actually rode 2 miles per hour on his trip
Step-by-step explanation: Maybe unconventional, but express the time it took, then figure the speed.
Time = distance /speed t will represent time, s is the speed: t = 30/s Use the rime it would have taken at the higher speed to create an equation:
t-12 = 30/s+8 replace the y with the 30/s
30/s -12 = 30/s+8
(s)(30/s -12 ) = (s)(30/s+8 ) Cross multiply to cancel denominators
(s-8)(30 -12s) = (s-8)(30s/s+8 ) ==> 30s +240 -12s² -96s =30s Simplify:
(-1)(-12s² -96s +240 ) =0 ==> 12s² +96s -240 divide all by 12
s² + 8s -20 = 0 Factor and solve for s
(s +10)(s -2) =0 s-2=0 S= 2
Proof:
30/2 = 15 hours for original trip at 2mph,
increase speed by 8mph 2 + 8 = 10mph
30 miles at 10mph takes 3 hours; that is 12 hours less than his actual trip.
(Brainilest, please :-)
$50
20 x 2 = 40, which is 80%
and then 20 divided by 2 is 10; so you add that to 40 and you get your answer
