Two infinitely long wires carry current in opposite direction and distance between them is gives as d. point A is in between wires at a distance x from first. Find x where magnetic field induced is minimum

Magnetic field due to a current carrying wire is given by, B=
2πr
μ
0
​
I
​

and for direction, point the thumb along the direction of current then curl the fingers around will represents the direction of the magnetic field.
In case of two infinitely long wires carrying currents in the same direction, the field due to both of them at a point P which is lying midway between them will cancel each other and their resultant will be zero.