Question

how we get to know that where we have to cross multiple and where not (ques from subject maths)​

Answer 1

Step-by-step explanation:

Multiplying the top and bottom of a fraction by the same amount doesn't change its value.

Step 1: Multiply the top and bottom of the first fraction by the bottom number of the second fraction.

8 × 312 × 3 = 23

Step 2: Multiply the top and bottom of the second fraction by the bottom number that the first fraction had.

8 × 312 × 3 = 2 × 123 × 12

And Magic! The bottom of both fractions is now 12 × 3

Step 3: We can get rid of the 12 × 3 (as we are dividing both sides by the same amount) and the equation is still true:

8 × 3 = 12 × 2