To find whether a pair is a solution of an equation, you plug in x and y by their respective value and if their is an equality, then it's a solution:
y = 2x+1
Is F(3,7) a solution? 7 = 2(3) +1 → 7 = 7 . YES, F(3,7) is a solution
Is G(0,1) a solution? 1 = 2(0) +1 → 1 = 1 . YES, G(0,1) is a solution
Is H(-1,1) a solution? 1 = 2(-1) +1 → 1 = 1 . YES, H(-1,1) is a solution
Is I(-3,-5) a solution? -5 = 2(-3) +1 → 5 ≠ -5 . NO, I(-3,-5) is NOT a solution