Question

What is the value of x in the solution to the following system of equations?

x − y = −3
x + 3y = 5

Answer 1

@pooja195 nope, what are the steps I can probably figure it out

Answer 2

you can use one of two methods, elimination or substitution

Answer 3

you would want to find the value of y because it will help you, once you substitute that y value back in to the second equation, to find x

Answer 4

\(x - y = -3\)
\(-y = -3 - x\)
\( y = 3 + x\)

substitute \(y = 3 + x \) to where y is in the second equation
\(x + 3(3 + x) = 5\)
\(x + 9 + 3x = 5\)
\(4x + 9 = 5\)
\(4x + 9 - 9 = 5 - 9\)
\(4x = -4\)
\(x = -1\)

Answer 5

did you understand?

Answer 6

Here's another way to solve it:
x − y = −3
x + 3y = 5

multiply the bottom equation by -1
x -y = -3
-x -3y = -5

add both equations
-4y = -8
y = 2

Answer 7

redsky - do you understand either method?