#" "5x+y+(−5x)=5+(−5x)" "#(Add #-5x# to both sides)
#" "y=−5x+5#.
Substitute #color(blue)((−5x+5))# for #color(blue)(y) " in " 3x+2y=3#:
#" "3x+2color(blue)(y)=3#
# 3x+2color(blue)((−5x+5))=3#
#3x-10x+10 =3#
# −7x+10=3#
# −7x+10+ (−10)=3+(−10)" "# (Add #-10# to both sides)
# −7x=−7#
#(7x)/-7=(-7)/-7" "# (Divide both sides by # -7#)
# x =1.#
Substitute #1 # for #x# in #y=−5x+5#
# y=−5x+5#
# y=(−5)(1)+5#
#y=0" " # (Simplify both sides of the equation).