Question

Which equation could use to solve x in the proportion 4/5=9/x

Answer 1

4/5 = 9/x
cross multiply
4x = 45 <===

Answer 2

`4\cdot x=45`

Explanation:

We have been given a proportion
`(4)/(5)=(9)/(x)`. We are asked to find the equation that could be used to solve for x.

To solve for x we will cross multiply our given equation as:

`4\cdot x=5\cdot 9`

`4\cdot x=45`

Now we will divide both sides of our equation by 4 as:

`(4\cdot x)/(4)=(45)/(4)`

`x=11.25`

Therefore, the equation
`4\cdot x=45` could be used to find the value of x.