For the following system, if you isolated x in the second equation to use the Substitution Method, what expression would you substitute into the first equation?

2x + y = 8
-x - 3y = -12

Question

For the following system, if you isolated x in the second equation to use the Substitution Method, what expression would you substitute into the first equation?

2x + y = 8
-x - 3y = -12

anonymous · Answer

did you solve for x in the second equation?  what did you get?

anonymous · Answer

no i dont understand it

anonymous · Answer

"isolate x" means to "solve for x"...
this basically means to get x only on one side of the equal sign...
so in the second equation....

anonymous · Answer

i know that. its just the equation is difficult.

anonymous · Answer

$\large -x-3y=-12 $
add -3y to both sides:
$\large -x-3y\color {red}{+3y}=-12\color {red}{+3y} $
$\large -x=-12+3y $
now you can multiply "-1" to both sides:
$\large -x\color {red}{\cdot(-1)}=(-12+3y)\color {red}{\cdot(-1)} $
$\large x=12-3y$

anonymous · Answer

thankk youuuuu

anonymous · Answer

yw...:)