Answer: it will take them 4 hours to be 640 kilometers apart.
Step-by-step explanation:
Let t represent the time it will take for both trains to be 640 kilometers apart. It means that the total distance that both trains will covered in t hours is 640 kilometers.
Distance = speed × time
A train leaves Little Rock Arkansas and travels north at 75 kilometers per hour. Distance covered after t hours would be 75 × t = 75t
Another train leaves at the same time and travels south at 85 kilometers per hour. Distance covered after t hours would be 85 × t = 85t
Since the total distance covered is 640 kilometers, then
75t + 85t = 640
160t = 649
t = 640/160
t = 4 hours
Laurie must make 4.5 batches for the school bake sale, and 2 batches for her family. Therefore, in total, Laurie must make 4.5 + 2 = 6.5 batches of cookies.
Since each batch of cookies requires 0.25 pounds of butter, we can multiply that amount by the number of batches baked: 0.25 * 6.5 = 1.625 pounds of butter.
So Laurie uses 1.625 pounds of butter to make all the cookies.
Answer:
f(x)=x-2x+3; f(x)=-bx
x-2x=3=-bx
x+4x+3=0
(x+3) (x+1) = 0
x=-3 or x=-1
when x+-3. f(x)=b x(-3)=18
x=-1. f(x) = - b x (-1) = b
so system of equations : ( -3, -18)
; (-),b
Step-by-step explanation:
hope it helps
This answer to this question is 4