Question

y varies indirectly as twice x. When x = 1, y = 3. Find y when x = 4.

Answer 1

x=1/2y+c (c is a constant)
1=1/(3*2) + c
c=5/6
4=1/2y +5/6
1/2y=(4-5/6)
2y=1/(4-5/6)
y=1/(2(4-5/6))