How do you solve by substitution #2x-y=23# and #x-9=-1#? Algebra Systems of Equations and Inequalities Systems Using Substitution 1 Answer Dean R. Apr 25, 2018 We write the second equation #x= 9 -1 = 8# and substitute into the first: #2(8) - y = 23# or #y = 2(8)-23=-7#. Explanation: Check #x=8, y=-7# # 2(8) - (-7) = 16 + 7 = 23 quad sqrt # # 8 - 9 = -1 quad sqrt # 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 8268 views around the world You can reuse this answer Creative Commons License