How do you solve this system of equations: #y= - 6x - 13 and 7x + 2y = - 16 #?

1 Answer
Dec 14, 2017

#(x,y)to(-2,-1)#

Explanation:

#y=-6x-13to(1)#

#7x+2y=-16to(2)#

#color(blue)"Substitute "y=-6x-13" into equation "(2)#

#rArr7x+2(-6x-13)=-16#

#rArr7x-12x-26=-16#

#rArr-5x-26=-16#

#"add 26 to both sides"#

#-5xcancel(-26)cancel(+26)=-16+26#

#rArr-5x=10#

#"divide both sides by "-5#

#(cancel(-5) x)/cancel(-5)=10/(-5)#

#rArrx=-2#

#color(blue)"substitute "" this value into equation "(1)#

#rArry=(-6xx-2)-13=12-13=-1#

#"the point of intersection "=(-2,-1)#
graph{(y+6x+13)(y+7/2x+8)((x+2)^2+(y+1)^2-0.04)=0 [-10, 10, -5, 5]}