4b = 0

`(4b)/4 = 0/4` division property of equality

`4/4*b/1 = 0/4` multiplicative property of fractions

`1*b/1 = 0/4` identity property

`b = 0/4` multiplication property of 1

b = 0 (1/4) multiplicative property of fractions

b = 0 multiplication property of zero.