The first inequality must be a solid line because of the presence of the ≤ sign
Look at graph c....(0,0) is in the shaded region
So note that 5(0) - 2(0) ≤ 10 = 0 ≤ 10 is true
So by process of elimination , graph d must go with 4
The second inequality is a shaded line because of the presence of the > sign
Test (0,0 ) into this inequality
3(0) > 3(0) + 9
0 > 9 is false
So graph b must go with 2 because (0,0) isn't contained in the feasible region
So....by process of elimination, a must go with 3