Your answer is -5.
This is because, if you expand the single bracket, you get -6x -3a, and since the other side of the equals sign is -6x + 15, then you need to do 15 ÷ -3 = -5.
I hope this helps!
Answer:
The speed of the wind is 
Step-by-step explanation:
Let
x-----> the speed of the wind in mph
we know that
Downwind
-----> equation A
Upwind
----> equation B
equate the equation A and the equation B
39 foot into 3 pieces
one is 13 feet
the other pieces add up to the
remaining wire
which is 39-13=26 so
the two remaining pieces are x and y
one must be 2 less than 3 times the
other
x must be 2 less than 3 times the y
x=-2+3y
x=3y-2
x+y=remaining=26
26=x+y
x=3y-2
subsitute
26=3y-3+y
add like terms
26=4y-2
add 2 to both sides
28=4y
divide by 4
7=y
subsitute
7+x=26
subtract 7
x=19
19>7
7 feet is the legnth of the shorter
piece
2/3b = 12
First you have to get rid of 2/3, so you multiply both sides by its reciprical:
(3/2) 2/3b = 12 (3/2) -->b = 36/2 --> b = 18
