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