Fun fraction

If you find the cross products, you get x^2 = 81. After finding the square root of both sides, you get the value of x: x = 9.

$\frac {3}{x} = \frac {x}{27}$

Cross multiply to get

$\frac {81}{27x} = \frac {x^2}{27x}$

Multiply boths sides by $27x$

$81 = x^2$

Square root

$x = 9$

The answer is $9$

$\frac{3}{x}=\frac{x}{27}$ Cross multiplying,we get $x^2=81$ as $x$ is positive,so $x=\boxed{9}$

using cross multiplication you would divide 27 and 3 to get 9

Just cross multiply:

$x^2 = 81$

$x = 9$

$\begin{aligned} \dfrac{3}{x} & = \dfrac{x}{27}\\ \\ x^2 & = 81\\ x & = \pm 9 \end{aligned}$
Since $x$ is positive, $x \neq -3$ . So, $x = \color{#69047E}{\boxed{9}}$ .

Well, knowing the rule of cross multiply, and 27 is multiples of 3 by 9. X = 9. It all make sense at the end, logic.

You can cross multiply so 3x27=x^2. Then simplify the left hand side: 81=x^2. Next square root both sides and you get 9 for x.

SIMPLY CROSS MULTIPLY TO GET x*2=81 so x=9

$\frac { 3 }{ x } =\frac { x }{ 27 } \\ { x }^{ 2 }=81\qquad \qquad By\quad cross\quad multiplication\\ { x }^{ 2 }={ 9 }^{ 2 }\\ Which\quad shows\quad that\quad \\ \boxed { x=9 }$

x^2=3x27 , x = square root of 81 = 9

square of 9 becomes 81 after cross multiplication

By Cross Multiplication (Property1 of Proportion) 3 × 27 = X × X, 81 = X^2 (Square root on both sides). 9 = X

x^2=81------------->x=9

81 = x^2 ; square root of 81 = x; x=9 :)

First of all we cross multiply
3/x=x/27 x^2=81 x=(81)^(1/2) x=9