-x^2 - 5x - 4 = -x^2 + 9x - 18
-5x - 9x = -18 + 4
-14x = -14
x = -14/-14
x = 1 <====
y = -x^2 - 5x - 4
y = (-1^2) - 5(1) - 4
y = 1 - 5 - 4
y = 1 - 9
y = -8 <====
Answer:
40 mph.
Step-by-step explanation:
Suppose grandma's house is 30 miles away (any distance would do but 30 is convenient).
Speed = distance / time
time = distance / speed
Time to get there = 30/60 = 1/2 hour.
Time to get back = 30/30 = 1 hour
Average speed = total distance/ total time
= (30 + 30) / ( 1 + 1/2)
= 60 / 1.5
= 40 miles per hour.
You cannot take the average of the speeds directly
(60+ 30)/2 = 45 is not correct as you cannot average ratios ( speed is a ratio).
Answer: 24 minutes it the correct answer you would do 40(60) = 2,400
Deducte the 0's and you have 24
1. 7/15 = 63/135
2. 6/13 = 48/104
hope this will help you