Question

What no. should be added to each of the no. 12,22,42 and 72 so that the resulting no. maybe in prportion.

Answer 1

Let the number which be added be x

So (12+x), (22+x), (42+x)and (72+x) are in proportion

So middle terms product = end terms product

(42+x)(22+x)=(12+x)(72+x)

924+64x+x^2=864+84x+x^2

924+64x=864+84x

60=20x

x=3

Answer 2

hey there!!!

let the no to be added be 'x'.

so nos will be 12+x,22+x,42+x,72+x.

so to be in proportion.

12+x   =   42+x  
22+x         72+x

(12+x)(72+x)=(42+x)(22+x)

12(72+x)+x(72+x) = 42(22+x)+x(22+x)

864+12x+72x+x^2=924+42x+22x+x^2

864+84x=924+64x

84x-64x=924-864

20x=60

x= 3

hope it helps you!!!!
if you have any doubts , pls let me know in the comments

mark it as brainliest ans pls !!!