If two tangent lines to a circle are drawn from a point, the length of those tangents are equal....thus,
11y = 3y + 4 subtract 3y form both sides
8y = 4 divide both sides by 8
y = 4/8 = 1/2
And AB = 3y + 4 = 3(1/2) + 4 = 3/2 + 4 = 1 + 1/2 + 4 = 5 1/2 = 11/2
