Add them up i think i never tried this
Answer:

Step-by-step explanation:
Let's calculate the answer to the second parenthesis. Just multiply throughout to get -8xyz. Then, multiply the first parenthesis by the second. Multiply the constants (-8 and 2) first to get -16, multiply the x's together to get x^2, the y's together to get y^2, and the z's together to get z^2. Put it all together to get
.
Y=-3x-2
subsitute -3x-2 for y
-7x+3(-3x-2)=10
distribute
a(b+c)=ab+ac
3(-3x-2)=-9x-6
-7x-9x-6=10
add like terms
-16x-6=10
add 6
-16x=16
multiply -1
16x=-16
divide 16
x=-1
subsitute
y=-3x-2
y=-3(-1)-2
y=3-2
y=1
x=-1
y=1
(x,y)
(-1,1)
Hello!
If y varies jointly with x and z, it'll mean that x and z are being multiplied by a factor "k", to equal y.
To give you a visual, this is what I mean.

That means we'll want to find
with the first point we're given: 



Which means our equation is:

Now, let's plug in the
and
from the other point to find
.


Hope this helps!
Answer: 32.20$ Train Fee
Step-by-step explanation:
15% of 28 is 4.20... 4.20 will be added to the current Train Fee
28.00$
<u> + 4.20$</u>
32.20$
Final result: The Train Fee will be 32.20$