7,2:2,4=0,9:x

To solve the equation 7.2 : 2.4 = 0.9 : x, you can use the concept of cross-multiplication.

Cross-multiplication involves multiplying the numerator of one fraction by the denominator of the other fraction.

In this case, you can multiply 7.2 (the numerator of the left fraction) by x (the denominator of the right fraction), and multiply 2.4 (the denominator of the left fraction) by 0.9 (the numerator of the right fraction).

So, the equation becomes:

7.2 * x = 2.4 * 0.9

Now, you can solve for x by dividing both sides of the equation by 7.2:

x = (2.4 * 0.9) / 7.2

Simplifying the right side gives:

x = 2.16 / 7.2

Now, divide 2.16 by 7.2:

x = 0.3

Therefore, x equals 0.3.