Answer:
S = v1 t1 = 7 t1 traveling downstream
S = v2 t2 = 5 t2 traveling upstream
7 t1 = 5 t2
7 (6 - t2) = 5 t2 since t1 + t2 = 6
42 - 7 t2 = 5 t2
t2 = 42 / 12 = 3.5 hrs so t1 = 2.5 hrs
S = 7 t1 = 7 * 2.5 = 17.5 mi
Also, S = 5 t2 = 5 * 3.5 = 17.5 mi
Try to get the u’s on one side so for this to happen, you would subtract the four from both sides.
u - 4u = 7 - 4
combine like terms
-3u = 3
divide by -3
u = -1
The area is A. 84 square inches
For the given trinomial

We need to multiply a by c

We split the middle term with these two factors

To obtain,

We now factor

This implies