Variables are represented by letters most of the time. These are all of the letter variables: a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, and z .
we all know 1+1=2 right? But did you know it can equal 2x? If you know algebra, you know what x equals. If you don't know algebra, this can take you farther into the world of math. x is an unknown number. 2x means 2 times x. So 1+1=2, and 2 times 1 equals 2.