X + y = 40.....multiply by -4
4x + 6y = 180
-------------------
-4x - 4y = -160 (result of multiplying by -4)
4x + 6y = 180
------------------add
2y = 20
y = 20/2
y = 10 <===
x = 30
Answer:
The truck travel must to have a constant speed of 
Step-by-step explanation:
we have

where
d expresses a car's distance in feet
t is the number of seconds
<em>Find the distance d for t=8 sec</em>

<em>Find the distance d for t=8.2 sec</em>

The total distance in this interval of 0.2 sec is

<em>Find the speed of the car</em>
Divide the total distance by the time

therefore
The truck travel must to have a constant speed of 
Answer:
thosyukfgg
Step-by-step explanation:
Answer:
<u>The</u><u> </u><u>solution</u><u> </u><u>is</u><u> </u><u>B</u>
Step-by-step explanation:

then:

therefore, interval [limits] of x:
