How do you solve #3x+5y=36# and #-9x+y=36# using substitution? Algebra Systems of Equations and Inequalities Systems Using Substitution 1 Answer ali ergin Mar 14, 2016 #y=4# #x=-4/3# Explanation: #color(red)(3x+5y)=color(green)(36)" (1)"# #color(red)(-9x+y)=color(green)(36)# #color(red)(3x+5y=-9x+y)# #3x+9x=y-5y# #12x=-4y# #x=-(4y)/12# #x=-y/3" "(2)# #"let's use the equation (1)"# #3(-y/3)+5y=36# #-y+5y=36# #4y=36# #y=36/9" "y=4# #"using the equation (2):"# #x=-4/3# 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 1396 views around the world You can reuse this answer Creative Commons License