Question 207890
(1) x + y = 60
(2)2x +6y = 192


The second equation has a 2x, while the first equation has only x.  You need to make the x terms subtract out, so in order to subtract out the 2x, you need a -2x.  To get that, you have to multiply the first equation by -2.  You could also have eliminated the y terms by multiplying the first equation by -6.  We usually try to eliminate using the smaller number.


R^2