The straight lines are asking to find the modulus or the size of the complex number.
For a complex number z = x + iy, [z] = √(x^2 +y^2)
Where x = Real Number, y = Imaginary number.
For 3 +i, x = 3, y = 1 (Note y is what number that is attached to i)
[3 + i] = √(3^2 +1^2) = √10 = 3.162
6 7/8= 55/8
6 1/6= 7/6
first find common denominators
55/8 * 3= 165/24
7/6 * 4= 28/24
165/24 divided by 28/24 is the same as 165/24 time 24/28
so that equals 3960/672
which equals 5.8928
so estimates about 5 shelves<span />
