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 How would you go about finding this?

Algebra ->  Graphs -> 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 How would you go about finding this?       Log On


   

Question 111366: 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
How would you go about finding this?

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
5x+%2B+7y+=+b Start with the first equation


5%28-3%29+%2B+7%284%29+=+b Plug in x=-3 and y=4. This is the solution (-3,4)


-15%2B28=+b Multiply

13=+b Add

So b=13



mx+%2B+y+=+22 Now move onto the next equation


m%28-3%29+%2B+%284%29+=+22 Plug in x=-3 and y=4


-3m%2B4=+22 Multiply

-3m=+18 Subtract 4 from both sides


m=+-6 Divide both sides by -3 to isolate m

So m=-6