SOLUTION: Find values for m and b in the following system so that the solution to the system is (-3, 4) 5x+7y=b mx+y=22 Thanks for any help you can give Heather

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Find values for m and b in the following system so that the solution to the system is (-3, 4) 5x+7y=b mx+y=22 Thanks for any help you can give Heather      Log On


   

Question 109733: Find values for m and b in the following system so that the solution to the system is (-3, 4)
5x+7y=b
mx+y=22
Thanks for any help you can give
Heather
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
b+=+5x+%2B+7y
substitute (-3,4)
b+=+5%2A-3+%2B+7%2A4
b+=+-15+%2B+28
b+=+13 answer
again, substitute (-3,4)
mx+%2B+y+=+22
mx+=+22+-+y
m+=+%2822+-+y%29+%2F+x note that x can't be 0!
m+=+%2822+-+4%29+%2F+-3
m+=+18%2F-3
m+=+-6 answer
check the answers
5x+%2B+7y+=+b
5%2A-3+%2B+7%2A4+=+13
-15+%2B+28+=+13
13+=+13
OK
mx+%2B+y+=+22
-6%2A-3+%2B+4+=+22
18+%2B+4+=+22
22+=+22
OK