Question

What same number should be added to each of the numbers 2.7.10 and 25 so
that they form a proportion?​

Answer 1

let the no. be x

(2+x)/(7+x)=(10+x)/(25+x)

(2+x)*(25+x)=(10+x)*(7+x)

${x}^{2} + 27x + 50 = {x}^{2} + 17x + 70$

10x=20

x=2