What is its equivalent resistance

Dear Student ,
Here in this case the resistors R and R₁ are in parallel with each other .
So their equivalent is , R' = RR₁ / (R+R₁ )
Now again R₃ and R₄ are also in parallel with each other .So their equivalent resistance is ,
R"= R₃R₄ / ( R₃ + R₄ )
So R' , R" and R₂ are in series so the equialent resistance of the circuit is ,

$R_{equivalent }=\frac{R{R}_1}{R+R_1}+R_2+\frac{R_3{R}_4}{R_3+R_4}$
Hope this helps you .
Regards