Question

Which of the following is the solution to 4/5 = 20/(x-5)?

Answer 1

`(4)/(5) = (20)/((x - 5))`

By Cross-multiplication

`\implies4 * (x - 5) = 20 * 5`

`\implies4x - 20 = 100`

`\implies4x = 100 + 20`

`\implies4x = 120`

`\implies \: x = \cancel (120)/(4)`

`\implies \: x = 30`

Answer 2

x=30

Explanation:

`(4)/(5)=(20)/(x-5) \\\\4(x-5)=20*5\\\\4x-20=20(5)\\\\4x=20(5)+20(1)\\\\4x=20(5+1)\\\\4x=20(6)\\\\x=(20(6))/(4) \\\\x=5*6\\\\x=30`