Question

6(1—a) =3(a—b)+1 4(b—2) =3a Consider the system of equations above. If (a, b) is the solution to the system, then what is the

Answer 1

6-6a=3a-3b+1,    9a-3b=5
4b - 8 =3a,           3a-4b=-8
 
9a-3b=5
(3a-4b=-8 )*(-3 )

 
9a    -3b=    5
-9a+12b=+24
adding both equations
9b=29, b=29/9

3a=4b-8=4*29/9 -8=(4*29-8*9)/9 = 44/9
a=44/27
a-b=44/27 - 29/9=44/27 - 29*3/27=-43/27
this is a correct answer, unfortunately they do not have this choice, probably they made mistake somewhere. I even check the solution of equations by substitution values of a and b into equations