If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to y from the second equation is substituted into the first equation.

2x – 7y = 4
3x + y = –17

Question

If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to y from the second equation is substituted into the first equation.

2x – 7y = 4
3x + y = –17

anonymous · Answer

So I'd solve for one variable in one equation. Let's go with the second one. 
That'd be y=-17-3x.
Now, plug that in for y in the original equation:
2x - 7(-17-3x) = 4
2x+21x+119=4
23x+119=4
23x=-115
x=-5
Now you have x. Substitute -5 for x in to any equation. Ill choose the second one. 
3(-5)+y=-17
-15+y=-17
y=-2

And there you have it. The answer to this systems of equations is (-5, -2).

Hope that helps!

anonymous · Answer

so out of these which one would it be? 2(3x – 17) – 7y = 4

2(–3x – 17) – 7y = 4

2x – 7(3x – 17) = 4

2x – 7(–3x – 17) = 4

anonymous · Answer

Well, here's a hint. The choices show the equation when y is substituted. What do you think?

anonymous · Answer

the last one?

anonymous · Answer

Yes, that's correct!