How do you solve the system of equations #x+ y = 8# and #- 2x + 3y = 9#?
1 Answer
Aug 6, 2018
Explanation:
#"we can use the "color(blue)"substitution method"#
#x+y=8to(1)#
#-2x+3y=9to(2)#
#"from "(1)tox=8-yto(3)#
#"substitute "x=8-y" into equation "(2)#
#-2(8-y)+3y=9#
#-16+2y+3y=9#
#"add 16 to both sides"#
#5y=9+16=25#
#"divide both sides by 5"#
#y=25/5=5#
#"substitute "y=5" into equation "(3)#
#x=8-5=3#
#"point of intersection is "(3,5)#
graph{(y+x-8)(y-2/3x-3)=0 [-10, 10, -5, 5]}