ANSWER
48
EXPLANATION
Two ratios are equivalent if they both simplify to the same ratio.
If we have ratio 7:4 - which is already simplified - and we want to know what's the equivalent ratio that starts with 84:__ we have to see by what number should we multiply 7 to get 84. Then, to fill in the blank, we have to multiply 4 by that number.
To find this number we just have to divide 84 by 7:
[tex]\begin{gathered} 7x=84 \\ x=\frac{84}{7} \\ x=12 \end{gathered}[/tex]If 7 times 12 is 84, then the number that's missing is 4 times 12:
[tex]4\cdot12=48[/tex]The equivalent ratio is 84:48
