<PRE><B>Question 571830</B>
Hello, 
We can set this y=43+5x  78=43+5x up as:
78=43+5x
Subtract 43 from each side:
35=5x
Now we could substitute this into the first equation:
y=43+35
Add and we get:
y=78
Or, a quicker way is substitute 43+5x into the first and we get:
y=78
Make sense?
RJ
www.math-unlock.com</PRE>