whats x in terms of c and a a/x+1=c/x ?

Do you mean a/x + 1 = c/x or a/(x + 1) = c/x ?????

Assuming the first, multiply all terms by x

This gives a + x = c so x = c - a

If it's the second, multiply by (x + 1) and by x

This gives ax = c(x + 1)

ax = cx + c

ax - cx = c

x(a - c) = c

x = c/(a - c)

Cross multiply

ax = c(x + 1)

ax /( x + 1) = c

ax = c(x + 1)

a = c(x + 1) / x

a(x+1) = c/x

ax = c(x+1)

c = ax/(x+1)

a = (cx + c)/x