Question

If (x+4): (3x+1) is the duplicate ratio of 3:4 find the value of x.​

Answer 1

x =
`(13)/(5)`

Explanation:

Express the ratios as equivalent fractions, that is

`(x+4)/(3x+1)` =
`(3)/(4)` ( cross- multiply )

3(3x + 1) = 4(x + 4) ← distribute parenthesis on both sides

9x + 3 = 4x + 16 ( subtract 4x from both sides )

5x + 3 = 16 ( subtract 3 from both sides )

5x = 13 ( divide both sides by 5 )

x =
`(13)/(5)`

Answer 2

Explanation:

According to the question:

(x+4) : = 3:4

or, (x+4) / (3x+1) = 3 / 4

or, (x+4) * 4 = (3x+1) * 3

or, 4x + 16 = 9x + 3

or, 16 - 3 = 9x - 4x

or, 13 = 5x

or, 13/5 = x

•

• • x = 2.6