+868 For certain values of $k$ and $m,$ the system
a + 2b = -3 - 7a + b,
4a + 2b = k - 5a - mb
has infinitely many solutions $(a,b).$ What are $k$ and $m?$
+129895 Simplify as
8a + b = -3
9a + (2 +m)b = k
This will have infinte solutions when the equations are the same...so....multiply the first equation by 9 and the second by 8 and we get
72a + 9b = -27
72a + 8 (2 + m)b = 8k
So
9 = 8(2 + m) and 8 k = -27
9 = 16 + 8m k = -27/8
-7 = 8m
m = -7/8
