Science

Math

Humanities

... and beyond

Socratic Meta
Featured Answers

Topics

How do you solve $2 x - 3 y = 4$ $2x-3y=4$ and $x + 4 y = - 9$ $x+4y=-9$ using substitution?

1 Answer

Jun 7, 2018

$x = - 1, y = - 2$ $x=-1,y=-2$

Explanation:

From the secon equation we get

$x = - 9 - 4 y$ $x=-9-4y$
plugging this in the first one

$2 (- 9 - 4 y) - 3 y = 4$ $2(-9-4y)-3y=4$
$- 18 - 8 y - 3 y = 4$ $-18-8y-3y=4$
so

$- 11 y = 22$ $-11y=22$

$y = - 2$ $y=-2$

Related questions

How do you solve systems of equations using the substitution method?
How do you check your solutions to a systems of equations using the substitution method?
When is the substitution method easier to use?
How do you know if a solution is "no solution" or "infinite" when using the substitution method?
How do you solve $y = - 6 x - 3$ $y=-6x-3$ and $y = 3$ $y=3$ using the substitution method?
How do you solve $12 y - 3 x = - 1$ $12y-3x=-1$ and $x - 4 y = 1$ $x-4y=1$ using the substitution method?
Which method do you use to solve the system of equations $y = \frac{1}{4} x - 14$ $y=1/4x-14$ and $y = \frac{19}{8} x + 7$ $y=19/8x+7$ ?
What are the 2 numbers if the sum is 70 and they differ by 11?
How do you solve $x + y = 5$ $x+y=5$ and $3 x + y = 15$ $3x+y=15$ using the substitution method?
What is the point of intersection of the lines $x + 2 y = 4$ $x+2y=4$ and $- x - 3 y = - 7$ $-x-3y=-7$ ?

See all questions in Systems Using Substitution

Impact of this question

4127 views around the world

You can reuse this answer
Creative Commons License