Let
be the speed of train A, and let's set the origin in the initial position of train A. The equations of motion are

where
are the positions of trains A and B respectively, and t is the time in hours.
The two trains meet if and only if
, and we know that this happens after two hours, i.e. at 

Solving this equation for v we have

So, train A is travelling at 105 km/h. This implies that train B travels at

Answer:
you didnt put an equation
Step-by-step explanation:
Answer:
C. -7x^2 - 28
Step-by-step explanation:
Firstly simplify the bracket before doing anything;
4x(3x - 7) = 12x^2 - 28x
then go back to the question and substitute the expression(12x^2 - 28x) on the bracket and then work out the question;
12x^2 - 28x -19x^2...then group the values with the same exponent of x,
(12x^2 - 19x^2) - 28x
; -7x^2 - 28x
Answer:
3cm
Step-by-step explanation:
A particular satellite is 15 m wide
Model of it was built with a scale of 1 cm: 5 m
=> scale of the model will be: 1/500cm and A particular satellite is 1500 cm wide
=>1500*1/500=3(cm)