Answer:
Step-by-step explanation:
Let the unknown value be x
[tex]42 = 3\\84 =x\\\\[/tex]
Cross Multiply
[tex]42\times x = 84\times 3\\\\42x = 252[/tex]
Divide both sides of the equation by 42
[tex]\frac{42x}{42} = \frac{252}{42} \\\\Simplify\\\\x =6[/tex]