How do you solve #7x+2y= -29# and #-8x+y=43# using substitution?
1 Answer
Apr 18, 2017
#x=-5#
#y=3#
Explanation:
Given -
#7x+2y=-29# -----------------(1)
#-8x+y=43# ------------------(2)
Solve the 2nd equation for
#y=43+8x#
Substitute
#7x+2(43+8x)=-29 #
#7x+86+16x=-29 #
#23x=-29-86 =-115#
#x=(-115)/23=-5#
#x=-5#
Substitute
#-8(-5)+y=43 #
#40+y=43#
#y=43-40=3#
#y=3#