Question

solve the proportion x/ x+1 = 4/ x+4

Answer 1

Well, you could cross-mulitply.

Answer 2

You know, x times x + 4 equals 4 times x + 1.

Answer 3

Visually it looks like:

x(x + 4) = 4(x + 1)

Answer 4

x(x+4) = 4(x+1)
x^2 + 4x = 4x + 1
x^2 - 1 = 0
(x-1)(x+1)
x=1 or x=-1