How do you solve the following system?: 3x +11y =-4, -9x +5y = 2

1 Answer
Jan 26, 2016

(x,y)=(-7/19,-5/19)

Explanation:

Solve by elimination:-

3x+11y=-4,-9x+5y=2

It is possible to eliminate -9x by 3x if we multiply 3x by 3 to get 9x

rarr3(3x+11y=-4)

rarr9x+33y=-12

Now add both of the equations:-

rarr(-9x+5y=2)+(9x+33y=-12)=(38y=-10)

rarr38y=-10

rarry=-10/38=-5/19

Now substitute the value of y to the first equation:-

rarr-9x+5(-5/19)=2

rarr-9x-25/19=2

rarr-9x=2+25/19=63/19

rarrx=63/19-:(-9)=63/19*(-1/9)=-63/171=-7/19

So,(x,y)=(-7/19,-5/19)