How do you solve the following system?: x +12y = 13 , 5x - 2y = -4x+12y=13,5x2y=4

1 Answer
Feb 3, 2016

(3/2,23/4)(32,234)

Explanation:

Because this question is in the section for using the Substitution method of solving systems of equations, that is the method I am going to use.

So, we start off with the equations:

x+12y=13x+12y=13
5x-2y=-45x2y=4

1) Set an equation equal to a variable

Since the first equation has a lone variable, on without a coefficient, I'm going to use that one, but you can use whichever one you want.

x+12y=13x+12y=13
color(red)(12-)x+12y=13color(red)(-12)12x+12y=1312
cancel(color(red)(12y-))x cancel(+12y)=13color(red)(-12y)
color(blue)(x=13-2y

2) Substitute the new equation into the other one

5x-2y=-4
color(blue)(x=13-2y
5(color(blue)(13-2y))-2y=-4
65-10y-2y=-4
65-12y=-4
color(red)(65-)65-12y=-4color(red)(-65)
cancel(color(red)(65-)65)-12y=-4color(red)(-65)
-12y=-69
(-12y=-69)/color(red)(-12)
y=color(green)5.75 or y=color(green)(23/4

3) Plug answer back into original equation

x=13-2y
x=13-2(color(green)(5.75))
x=13-11.5
x=color(orange)1.5 or y=color(orange)(3/2

4) Write the solution as a coordinate (x,y)

The solution is: (color(orange)(3/2),color(green)(23/4))