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

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Answer 1 · 2018-04-14T05:31:08

$(- 3, 4)$ $(-3,4)$

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

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

$- y - 15 = - 19$ $-y-15=-19$

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

$3y-15=x$

$3(4)-15=x$

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

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

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

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