elementary algebra
posted by mary .
(3b+1)^2=16

(3b+1) (3b +1) = 16
9b^2 + 3b +3b + 1 = 16
9b^2 + 6b + 1 = 16
9b^2 + 6b + 1 16 = 1616
9b^2 + 6b 15 = 0
3(3b^2 + 2b 5) = 0
3(b1)(3b+5) = 0
b  1 = 0 3b + 5 = 0
b 1+1 = 0 + 1 3b + 5  5 = 05
b = 1 3b = 5
3b/3 = 5/3
b = 5/3
b = 1, 5/3 
(3b+1)^2=16
3b+1 = ±4
3b+1 = 4
b = 1
or
3b+1 = 4
b = 5/3