Question

How do you solve the following linear system: `3y-15=x , x-4y=-19`?

Answer 1

`(-3,4)`

Explanation:

We can substitute the first equation, `3y-15=x`, into the second equation, `x-4y=-19`:

`(3y-15)-4y=-19`

`-y-15=-19`

`-y=-4=>color(blue)(bar(ul(abs(color(black)(y=4))))`

`3y-15=x`

`3(4)-15=x`

`12-15=x=>color(blue)(bar(ul(abs(color(black)(x=-3`

And we can see that when we graph the two lines:

graph{(3y-x-15)(x-4y+19)=0[-10,10,0,10]}