need help solve the system of equations by graphing then classify the system as consistent or inconsistent, and as dependent or independent
4x-y=15
x+5y=-12 step by step plz

Question

need help solve the system of equations by graphing then classify the system as consistent or inconsistent, and as dependent or independent 
4x-y=15 
x+5y=-12 step by step plz

anonymous · Answer

First step, rewrite them as y=mx + b

anonymous · Answer

Check the consistency by matrices..

anonymous · Answer

These are linear equations in two variables
If they have a common solution, then they will cross each other at a point and hence will be consistent.
We put them in the form ax + by + c = 0 
4x - y - 15 = 0  and
  x + 5y + 12 = 0

Now If $$a1/a2 \neq b1/b2$$
then they will intersect at one point and will have a unique and consistent solution
Here a1/a2 = 4/1  and b1/b2 = -1/5

Since a1/a2 is not equal to b1/b2, therefore it will have a unique solution and they are consistent.