The Brainliest Answer!

This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
R1, R2, R3  each of  6 Ω

a)   Equivalent resistance of  9 Ω
       9 - 6 = 3  ohms...  
         3 = 6 / 2....
     so    R1  +   R2 R3 / (R2 + R3)  = 9 Ω
     we connect  R3 and R2 in parallel.   Then we connect R1 in series with them.

b)  we use one of the resistances only to get 6 Ω.  We cannot make a series or parallel combination of 3 resistances to get  6 Ω again.

2 5 2
click on thanks button above please