Respuesta :

7b / 12 = 4.2

4.2 * 12 = 50.4

50.4 / 7 = 7.2
Lilith
[tex]\frac{7b }{12} = 4.2 \ \ /*12 \\ \\7b=4.2*12\\ \\7b= 50.4 \ \ \/:7\\ \\\frac{7}{7} \ b= \frac{50.4 }{7}\\ \\b= 7.2[/tex]