A algebraic speed, distance, time type of problem - any help appreciated!

[aphrvdite]

hey hey!

I'm stuck on the 3rd part (part c) of a problem. Here it is:

Now, I have part a) which I solved to be as...

T=D/S, thus,
T₁= x/8
T₂= y/10

These are the answers to Part A, and they are correct and I understand this part.



I, too, have Part b) in which...

S=D/T, where

D = x+y
T = x/8+y/10

Hence, S = x+y / (x/8+y/10)
S = 80(x+y)/10x+8y

This too, I understand and have a correct answer to.


HOWEVER, with part c) this is my attempt so far...

Naturally, there is no solution to this attempt. I'm confident that this is meant to be a simultaneous equation kind of question, it's just that my actual equations seem to be off. What am I doing wrong?

Any help would be appreciated! <3

 

[blamocur]

A question on Equation 1: is not it a part of the problem statement that x+y = 70?
On part C): you have expressions for [imath]T_1[/imath] and [imath]T_2[/imath] from part A) -- can you use them for part C) ?