how do I solve simultaneous equations

3x+y=7 2x+y=6

Answers
hi there if you'd like me to take you through the different methods in detail it might be worth having a private session
chloe
12 May 2011
looks to me like this one will work best with the substitution method
chloe
12 May 2011
so if we re-arrange the first equation 3x +y = 7 to get y on its own we can subtract 3x from both sides to get:
chloe
12 May 2011
then we take the second equation and substitute this 7-3x in for the y that's already there to get:
chloe
12 May 2011
so now we know that
chloe
12 May 2011
and rearrange (because 6-7 = -1)
chloe
12 May 2011
now all we have to do is simplify:
chloe
12 May 2011
so for this becomes
chloe
12 May 2011
so all we have to do now is put the value of x=1 back into one of the original equations to find out what y is
chloe
12 May 2011
and subtracting 3 from each side we get
chloe
12 May 2011
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