Answer:
8
Step-by-step explanation:
10 + 8 = 18
18 x 2 = 36
Dale drove to the mountains last weekend. there was heavy traffic on the way there, and the trip took 7 hours. when dale drove home, there was no traffic and the trip only took 5 hours. if his average rate was 18 miles per hour faster on the trip home, how far away does dale live from the mountains? do not do any rounding.
Answer:
Dale live 315 miles from the mountains
Step-by-step explanation:
Let y be the speed of Dale to the mountains
Time taken by Dale to the mountains=7 hrs
Therefore distance covered by dale to the mountain = speed × time = 7y ......eqn 1
Time taken by Dale back home = 5hours
Since it speed increased by 18 miles per hour back home it speed = y+18
So distance traveled home =speed × time = (y+18)5 ...... eqn 2
Since distance cover is same in both the eqn 1 and eqn 2.
Eqn 1 = eqn 2
7y = (y+18)5
7y = 5y + 90
7y - 5y = 90 (collection like terms)
2y = 90
Y = 45
Substitute for y in eqn 1 to get distance away from mountain
= 7y eqn 1
= 7×45
= 315 miles.
∴ Dale leave 315 miles from the mountains
It is an irrational number
Answer:
x = -2 0r x = 6
Step-by-step explanation:
from the question
X² – 4x – 12=0
solve by completing the square method
we have;
X² – 4x – 12=0
X² – 4x = 12
to make the left hand side a perfect square we add 4 to both sides.
X² -4x + 4 = 12 + 4
X² -4x + 4 = 16
from left hand side X² -4x + 4
= (x -2) × ( x -2)
it can be simply expressed as
( x-2)²
so since X² -4x + 4 has been simplified to be ( x-2)²
then,
( x-2)² = 16
x - 2 = √ 16
since square root has two values it can either be positive or negative
so we have
x = 2 + √16
or
x = 2 - √16
therefore
x = 2 + √16
x = 2 + 4
x = 6
0r
x = 2 - 4
x = -2
Answer:
B =
Step-by-step explanation:B + C would be 8 because B=2 and C=5. 5 + 8 is 8
