7b÷12=4.2 what does b equal

" 7b ÷ 12 " can be written as " 7b / 12 ". That makes the problem easier,
because we know a lot of things that we can do with fractions.

                       7b / 12 = 4.2

Multiply each side of the equation by  12:

                       7b = (4.2 x 12) = 50.4

Divide each side of the equation by  7 :

                         b  =  50.4 / 7 = 7.2