How do you solve the system #w + z = 14# and #w - 2z = 2# by substitution?

1 Answer

# w+z = 14#
# w= color(red)(14-z#......equation#(1)#
# w - 2z = 2#.....equation #(2)#

Substituting equation #(1)# in #(2)#
#color(red)(( 14-z))-2z =2#
# 14 - 3z = 2#
# - 3z =- 12#
#z = 12/3 = 4#

Substituting #z# in equation #(1)# to find #w#
# w= 14-z#
# w= 14-4 = 10#

The solution for the system of equations is
# color(blue)(z = 4, w=10#