Question

what number should be subtracted from -8/15 to get 19/25​

Answer 1

Your wording is funny but I think you are seeking a number x so the following proportion holds:

(25-x)/(13-x) = (55-x)/(25-x)

Cross multiplying gives

625–50x+x^2 = 715–68x+x^2

18x=90

X=5

And indeed subtracting 5 from the original numbers gives: 8,20,50 which have constant ratio 2.5 (ie they are an geometric sequence)

Khushi... ☺☺

Answer 2

Answer:

-8/15-x =19/25

-x=19/25+8/15

-x=97/75

x= -97/75