Right firstly with simultaneous equations you'd work them out like so:Quote:
Originally Posted by clueless
3x + 8y = -1
7x - 6y = 47
Because the signs are different (+ and -) we add together the values.
Firstly we need to get at least on set of values the same so lets say the y's.
x3 9x + 24y = -3
x4 28x + 24y = 188
so as we add the values:
37x = 185
185 / 37 = 5
so x=5
if we put that back into the original equation:
15 + 8y = -1
35 - 6y = 47
therefore as 35 take away something cannot be 47 6y MUST be a negative as - and - make a +.
6y therefore must equal:
12 / 6
^ y = -2
we can put this back into the first equation to check:
15 + - 16 = -1
:) I hope you understand that now.
The other ones will work in a similar way however you'll have to do it differently on the graph but just remember the fundamentals as you should think of simultaneous equations as just like on a graph where the intersect is your value :).
I think I've explained this right - just read over whatever notes you took in class etc.
