Can someone walk me through completing the square with this equation: r^2 + 6r = 16?

Roots: 2, -8

Step-by-step explanation:

Use of formula: a^2+2ab+b^2= (a+b)^2

Below steps show how to complete square and solve the equation:

r^2 + 6r = 16r^2 + 2*3*r = 16                    adding below missing part of equation,  and completing squarer^2 + 2*3*r + 3^2= 16+ 3^2(r+3)^2= 25r+3= ± 5r= - 3 ± 5r= 2, r= - 8

Roots are 2 and - 8