How do you solve x = y - 1 and y = 4 - 2x? Algebra Systems of Equations and Inequalities Systems Using Substitution 1 Answer Lucy May 5, 2018 #y=2# #x=1# Explanation: #x=y-1# --- (1) #y=4-2x# --- (2) Sub (1) into (2) #y=4-2(y-1)# #y=4-2y+2# #3y=6# #y=2# --- (3) Sub (3) into (1) #x=y-1# #x=2-1# #x=1# Answer link Related questions How do you solve systems of equations using the substitution method? How do you check your solutions to a systems of equations using the substitution method? When is the substitution method easier to use? How do you know if a solution is "no solution" or "infinite" when using the substitution method? How do you solve #y=-6x-3# and #y=3# using the substitution method? How do you solve #12y-3x=-1# and #x-4y=1# using the substitution method? Which method do you use to solve the system of equations #y=1/4x-14# and #y=19/8x+7#? What are the 2 numbers if the sum is 70 and they differ by 11? How do you solve #x+y=5# and #3x+y=15# using the substitution method? What is the point of intersection of the lines #x+2y=4# and #-x-3y=-7#? See all questions in Systems Using Substitution Impact of this question 2453 views around the world You can reuse this answer Creative Commons License