Given x = 5
We will find which equation will give a solution x = 5
1) x/2 = 10
so, x = 2 * 10 = 20
So, option (1) is wrong
2) x - 7 = 12
x = 12 + 7 = 19
So, option 2 is wrong
3) 2 + x = 3
x = 3 - 2 = 1
So, option 3 is wrong
4) 3x = 15
x = 15/3 = 5
So, the answer is option 3x = 15
