How do you solve this system of equations: -8x - y = 14 and - 5x + y = 12?

2 Answers
Sep 24, 2017

x=-2 and y=2

Explanation:

Equation 1: -8x-y=14
Equation 2: -5x+y=12

To solve these equation try to remove one variable.

equation 1 +equation 2
-8x-y-5x+y=14+12
=>-13x=26
=>x=-2

Substitute value of x in any of equation.
Substituting value of x in equation 2

-5(-2)+y=12
=>10+y=12
=>y=2

Sep 24, 2017

(x,y)to(-2,2)

Explanation:

-8x-y=14to(1)

-5x+y=12to(2)

"using the "color(blue)"substitution method"

"from "(2)" express y in terms of x"

rArry=12+5xto(3)

color(blue)"substitute "y=12+5x" into "(1)

-8x-(12+5x)=14

rArr-8x-12-5x=14

rArr-13x-12=14

"add 12 to both sides"

-13xcancel(-12)cancel(+12)=14+12

rArr-13x=26

"divide both sides by - 13"

(cancel(-13) x)/cancel(-13)=26/(-13)

rArrx=-2

"substitute this value into "(3)

rArry=12+(5xx-2)=12-10=2

rArr"point of intersection "=(-2,2)
graph{(y-5x-12)(y+8x+14)((x+2)^2+(y-2)^2-0.04)=0 [-10, 10, -5, 5]}