How do you solve #2a=8# and #a+b=2# using substitution? Algebra Systems of Equations and Inequalities Systems Using Substitution 1 Answer MeneerNask Feb 10, 2017 If #2a=8->a=8/2=4# Explanation: In the second expression we may replace #a=4# #->4+b=2# now subtract #4# on both sides: #->cancel4-cancel4+b=2-4->b=-2# 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 1250 views around the world You can reuse this answer Creative Commons License