How do you solve #4x+3y=-22# and #-8x+y=58# using substitution?

1 Answer
May 28, 2018

Answer:

#x = 193/22 and y = 1410/11#

Explanation:

#4x + 3y = -22 - - - eqn1#

#-8x + y = 58 - - - eqn2#

By Substitution Method..

From #eqn2#

#-8x + y = 58 - - - eqn2#

Making #y# the subject formula..

#-8x + y = 58#

Add both sides by #8x#

#-8x + y + 8x= 58 + 8x#

#y = 58 + 8x - - - eqn3#

Substituting #eqn3# into #eqn1#

#4x + 3y = -22 - - - eqn1#

#4x + 3(58 + 8x) = -22#

#4x + 174 + 24x = -22#

#4x + 24x + 171 = -22#

#28x + 171 = -22#

#28x = -22 - 171#

#28x = 193#

#x = 193/22#

Substituting the value of #x# into #eqn3#

#y = 58 + 8x - - - eqn3#

#y = 58 + 8(193/22)#

#y = 58 + 1544/22#

#y = (1276 + 1544)/22#

#y = 2820/22#

#y = 1410/11#

Therefore;

#x = 193/22 and y = 1410/11#