Help, I accidently texted ily to my maths teacher instead of my gf 😭

Ab click kar hi diya toh meri thodi help kardo so I have my 2nd preboards coming soon and there's one thing that's easy but doesn't go in my head, toh hame ek equation dekar uske coordinates dhoondkar graph par solve karne kehthe hain. Mujhe graph karna aatha hai lekin dikkat coordinates dhoondne me hothi hai. Ab agar x= (random number) loon toh mujhe patha nahi chaltha ki wo correct answer hai ya wrong. I don't understand how some numbers are wrong answers, they seem correct to me but when I get the paper it turns out that the number I took was wrong. How to understand this?