Question

5 : 2 = 15 : x great answer get 20 points

Answer 1

Looking at this problem, it looks like we are given a ratio and inside of that ratio we are given an unknown variable, x, which we need to determine. The first thing that we should do is convert this into a fraction where the first number is the numerator and the second number is the denominator.

Convert to fractions

• 
  `5 : 2 = 15 : x`

• 
  `(5)/(2) = (15)/(x)`

Now that we have an equation set-up, we can now cross multiply which will give us the ability to then solve for x and get the value of the unknown.

Cross-Multiply

• 
  `5(x) = 15(2)`

• 
  `5x = 30`

We now have a simple equation which is easy to solve and can be done by dividing both sides by 5. This would remove the coefficient in front of the unknown variable and allow us to see the value of the unknown.

Divide both sides by 5

• 
  `(5x)/(5) = (30)/(5)`

• 
  `x = (30)/(5)`

• 
  `x = 6`

After simplifying the expression we were able to determine that the unknown value of x would be equal to 6 using cross-multiplication and simple math.

Answer 2

Explanation:

Proportion Given

5/2 = 15/x

Solution

5/2 = 15/x Cross multiply

5x = 2 * 15 Combine

5x = 30 Divide by 5

5x/5 - 30/5

x = 6

Answer: 6