systems of equations : y=x-3
4x+y=32
how do you solve this?

Question

systems of equations  : y=x-3
4x+y=32
how do you solve this?

anonymous · Answer

You know that y=x-3.
You can use this in y our second equation to solve for x
4x+(x-3)=32
5x-3=32
5x=35
x=7
Now you know x, so you can substitute 7 for x in y=x-3.
y=7-3=4
You can check if it's correct by plugging both values back into the other equation:
4(7)+4=32=28+4=32.
The expression is true, so those are the solutions.

anonymous · Answer

wait is y already solved?

anonymous · Answer

No, y is not already solved.  I had to solve it after I found x here.  We substituted x-3 for y in the other equation so we could solve for x.

anonymous · Answer

$$4x+y=4x+(x-3)=32$$