<span>In a system of linear equations we should first try to eliminate one variable. Like this:2a+2x=18........................(1)a+3x=17........................(2)Multiply equation (2) with 2:2a+6x=34....................(3)Subtract 1) and (3):-4x=-16x=4Substitute in 1) or 2) to get 'a' value:a=5Therefore the solution is x=4 and a=5...................(Answer)</span>