exam Maths Puzzle Numerical Ability

This has me so confused. Can somone help me.

The combined resistance of two resistors R1 and R2 in a parallel circuit is given by the formula R=1/(1/R1+1/R2)
Simplify the formula.

Read Solution (Total 0)

exam Other Question
b+4b=-90 2/sqrt[3] + sqrt[2]
Can you help me rationalize the denominator? I really apprecuate your help. It would help so much if you could show me how you do this.