Question

What should be added to each of the numbers 39,42,9 and 10 to get the numbers which are in proportion?​

Answer 1

Step-by-step explanation:

(39 + x) / (42 + x) = (9 + x) / (10 + x) or

(39+x)(10+x)=(42+x)(9+x). or

390+49x+x^ ^ 2=378+51x+x^ ^ 2 , or

2x = 390 - 378 = 12 .

Or x = 6 .

Check: 45/48 = 15/16

(9 + 6) / (10 + 6) = 15/16 . Correct.

So you need to add 6 to each of the 4 numbers: 39, 42, 9 and 10 so that they are in proportion.