Question

Calculate the X value a. 4: 7 = x: 5x: 8 = 99 :5

Answer 1

Start writing the proportion as a fraction

`\begin{gathered} 4\colon7\rightarrow(4)/(7) \\ x\colon5\rightarrow(x)/(5) \end{gathered}`

then, the ratios must be the same meaning we can equal the fractions

`\begin{gathered} (4)/(7)=(x)/(5) \\ \text{cross-multiply and solve for x } \\ x=4\cdot(5)/(7) \\ x=(20)/(7) \end{gathered}`

repeat the same procedure for b

`\begin{gathered} x\colon8\rightarrow(x)/(8) \\ 99\colon5\rightarrow(99)/(5) \\ \text{then,} \\ (x)/(8)=(99)/(5) \\ x=8\cdot(99)/(5) \\ x=(792)/(5) \end{gathered}`