normally you use x and y because it is usually (x,y), and not (y,x) so assume a=x and y=b
an easy way is to make one side equal to x then subsitue so
4x-5y=24
add 5y to both sides
4x=24+5y
divide both sides by 4
x=6+5/4y
subsitute and solve
A 6,0 where 6=x and 0=y
6=6+(5/4)(0)
6=6+0
true
A works
B where -2=x and -5=y
-2=-6+(5/4)(-5)
-2=-6-25/4
this is obviously false so B doesn't work
C where x=0 and y=6
0=6+(5/4)(6)
0=6+30/4
0=6+15/2
this is obviously false so C doesn't work
D where x=-5 and y=-2
-5=6+(5/4)(-2)
-5=6+(-10/4)
-5=6-5/2
this is obviously false so D is wrong
if the format is (a,b) or if a=x and b=y then the answer is A,
if the format is (b,a) or if b=x and a=y then the answer is C
