Question

Make u the subject-
1) a=1/u + 1/2

Answer 1

u=2/2a-1

Explanation:

a=1/u +1/2

you find the LCM first which is 2u

a=2+u/2u

cross multiply

2au=2+u

subtract u from both sides

2au-u=2

u is common to the right hand side

u(2a-1)=2

divide through by 2a-1

u=2/2a-1