Question

Solve for x 3:21=x:16

Answer 1

Given:
`3:21 = x:16`

Find: The value of the unknown variable, x

Solution: The first step that we should take is to convert the ratios into a fraction so we can then easily cross multiply, isolate the unknown variable, and simplify the expression.

Convert to fractions

• 
  `3:21=x:16`

• 
  `(3)/(21)=(x)/(16)`

Cross multiply

• 
  `3(16) = 21(x)`

• 
  `48 = 21x`

Divide both sides by 21

• 
  `(48)/(21) = (21x)/(21)`

• 
  `(48)/(21) = x`

Simplify the expression

• 
  `(48/3)/(21/3) = x`

• 
  `(16)/(7) = x`

Therefore, the final answer would be that the unknown would be equal to 16/7 in the ratio expression that was provided in the problem statement.

Answer 2

16/7 =x

Explanation:

We can use ratios to solve

3 x

----- = ---------

21 16

Using cross products

3*16 = x *21

48 = 21x

Divide by 21

48/21 = x

16/7 =x