What are the 2 numbers if the sum is 70 and they differ by 11? Algebra Systems of Equations and Inequalities Systems Using Substitution 1 Answer seph Nov 1, 2014 #x + y = 70# #x - y = 11# Add the two equations #(x + y) + (x - y) = 70 + 11# #2x = 81# #x = 40.5# #x + y = 70# #40.5 + y = 70# #y = 70 - 40.5# #y = 29.5# Your two numbers are #40.5# and #29.5# 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#? 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#? How do you solve #x-5y=15# and #4x-3y=26# using substitution? See all questions in Systems Using Substitution Impact of this question 10448 views around the world You can reuse this answer Creative Commons License